What PSSO means and when you use it

PSSO stands for "pass slipped stitch over." It is a decrease that removes one stitch from your needle by slipping a stitch, knitting the next stitch, then pulling the slipped stitch over the knitted one. The result looks like a left-leaning decrease — the opposite slant of a knit two together (K2tog).

You will see PSSO in patterns when the designer wants a decrease that leans left. Common uses are raglan sleeves, shaping the sides of garments, and decorative decreases in lace patterns. Some patterns call it "slip, knit, pass slipped stitch over" or abbreviate it as SKP or SKPO (slip, knit, pass over).

The stitch itself is straightforward once you understand the three-step motion. It takes the same number of stitches off the needle as K2tog, but the visual direction of the decrease is different — which matters when you are shaping symmetrically or following a stitch pattern that depends on the lean.

Key Takeaways

  • PSSO is a left-leaning decrease made by slipping one stitch, knitting the next stitch, then passing the slipped stitch over the knitted stitch.
  • The three steps must happen in order: slip, knit, pass over — doing them out of sequence changes the result.
  • PSSO and K2tog both remove one stitch, but PSSO leans left while K2tog leans right, so they are not interchangeable in a pattern.
  • You can work PSSO on any row — knit rows, purl rows, or ribbing — by adjusting which stitch you slip and which you knit.

The three steps of PSSO on a knit row

Start with at least two stitches on your working needle. Insert your right needle through the first stitch on the left needle from left to right, as if you were going to knit it. Slip that stitch onto the right needle without knitting it. You now have one slipped stitch on the right needle.

Knit the next stitch on the left needle normally. You now have two stitches on the right needle: the slipped stitch and the newly knitted stitch.

Insert the tip of your left needle into the slipped stitch (the one closer to the tip of the right needle). Lift it up and over the knitted stitch and off the right needle entirely. You have now decreased by one stitch. The knitted stitch remains on the right needle, and the slipped stitch is gone.

PSSO on a purl row

The motion changes slightly when you are working on the wrong side. Slip the first stitch purlwise (insert the needle as if to purl, then slip without purling). Purl the next stitch normally. Then pass the slipped stitch over the purled stitch, using your left needle to lift it over and off.

The result is the same decrease, but because you are working from the opposite side, the slant appears reversed on the right side of the fabric. This is why some patterns specify "PSSO on RS rows" or "PSSO on WS rows" — the designer is controlling which direction the decrease leans when you look at the finished piece.

PSSO versus K2tog and other decreases

K2tog (knit two together) removes two stitches into one by inserting the needle through both stitches at once and knitting them as a single stitch. The result leans right. PSSO leans left. In a symmetrical shaping pattern — say, decreasing one stitch on each side of a sleeve — you would use K2tog on one side and PSSO on the other to make the decreases mirror each other.

A third common decrease is SSK (slip, slip, knit), which also leans left and is often used interchangeably with PSSO. The difference is technical: SSK slips two stitches separately, then knits them together through the back loop, while PSSO slips one, knits one, then passes. Both create the same left-leaning visual result, though some knitters find one easier to execute than the other.

If a pattern calls for PSSO and you cannot get the tension right, SSK is usually a safe substitute. If a pattern calls for K2tog, PSSO will not work — the decrease will lean the wrong way and throw off the pattern's symmetry.

Common mistakes and how to avoid them

The most frequent error is passing the wrong stitch over. After you knit the second stitch, you must pass the slipped stitch (the older one) over the knitted stitch (the new one), not the other way around. If you pass the knitted stitch over the slipped one, you have made a different decrease entirely.

Another mistake is knitting the slipped stitch instead of slipping it. If you knit the first stitch, you have not decreased — you have just made a regular knit stitch. The slip must be a true slip: the stitch moves to the right needle without being worked.

Tension is the third common issue. If your slipped stitch is too loose, the pass-over will look sloppy. If it is too tight, the decrease will bunch. Aim for the same tension you use on regular knit stitches, and the stitch will blend into the fabric.

Reading PSSO in a pattern

Patterns abbreviate PSSO in different ways. You may see "PSSO," "pass slipped stitch over," "SKP" (slip, knit, pass), or "SKPO." Some older patterns write it out in full: "slip 1, knit 1, pass slipped stitch over." All of these mean the same thing.

Pay attention to whether the pattern specifies which row to use PSSO on. If it says "PSSO on RS rows only," work it only on right-side rows. If it says "PSSO on every row," work it on both knit and purl rows, adjusting the slip and knit steps as needed. The placement matters because it controls the visual direction of the decrease in the finished fabric.

Frequently Asked Questions

Can I use PSSO and K2tog in the same pattern?

Yes, and many patterns do this intentionally. PSSO leans left, K2tog leans right. In symmetrical shaping — like decreasing on both sides of a sleeve — using PSSO on the left side and K2tog on the right side makes the decreases mirror each other. If a pattern does not specify which decrease to use on which side, you can choose based on the lean you want.

What is the difference between PSSO and SSK?

Both are left-leaning decreases and produce nearly identical results. PSSO slips one stitch, knits one, then passes the slipped stitch over. SSK slips two stitches separately, then knits them together through the back loop. They look the same in the finished fabric, so if a pattern calls for one and you prefer the other, you can substitute.

Do I slip the stitch knitwise or purlwise?

On a knit row, slip knitwise (insert the needle as if to knit). On a purl row, slip purlwise (insert the needle as if to purl). This keeps the stitch in the correct orientation so the pass-over works smoothly and the decrease sits flat in the fabric.

What if I slip the stitch but forget to knit the next stitch?

You have not made a decrease — you have just moved a stitch. Go back and knit the second stitch, then pass the slipped stitch over. If you have already moved on, you will need to drop back and fix it, because the stitch count will be wrong.

Does PSSO work in ribbing?

Yes. In a knit-purl ribbing, slip and knit the stitches as the pattern dictates, then pass over. The decrease will sit within the ribbed texture. If you are decreasing a knit stitch, slip and knit as normal. If you are decreasing a purl stitch, slip purlwise and purl, then pass over.