this shirt is 100%polyester. it had really good reviews so I bought 2 of them and I'm glad I did. I usually wear a 2x in shirts. All the review I read said to get 3x so I did. it is so hard to for me to keep the shirts wrinkle free. I do not use an iron often as I probablyshould. these shirts a comfortable and nice looking for work. I plan on purchasing more of these in different colors!