Is it possible to unshrink a 100% cotton long sleeve polo shirt?

You can try washing it again in cold water, hang it until almost dry and then put it on and pull it down and out by hand. Sometimes this can work.

@janbb, will try tonight. thanks

All you can do is wear it and see if it will stretch out some. Cotton always shrinks on me, even the stuff I’ve washed and worn before. If has shrunk too much, you won’t get it stretched back to where you want it.

Wear it around the house, where you won’t look too funny in tight clothes. I am willing to bet you may stretch it out some. In the future, don’t wash in hot water and then don’t put it in the dryer. Hang it to dry. Hanging it upside down, using clothes pins to attach it to a hanger that hangs on your shower will stretch it nicely.

You can try to stretch it a little when it’s wet, but your not going to get more than a half an inch maybe. Sucks. :(. Wearing it won’t help in your case, because the shrink you are most concerned about is the length. That us usually the case with me too.

I shrink things by mistake all the time. I think it’s just absolutely awful when manufactures don’t used preshrunk cotton.

I almost never buy rayon because if the shrinking. Pisses me off.

I get quite a bit of length out of cotton by stretching it.

Pants, I stand on the hem and pull up. Even starting dry, I probably get more than an inch.

With a shirt, I would start out when it’s wet and go the same thing before you dry it at all. Grab a hold of the hem and shoulder and pull all you think the fabric can stand without tearing. Gradually work your way across the shirt, pulling. Then low heat dry until almost dry and check the length. If it’s good, hang it up to dry. If you need it a little longer, repeat, but pulling more gently and evenly.
If you really like the shirt I think you can get it back. Short-wasted is the current fashion, you know. :)