Stretchy material but the kind that will hold its shape are you wash. It runs small I am in a 12-14 and I needed a XXL but it does fit very nicely. l will order this again as I think it was worth the price. It is not like the spandex type of material that I have received on so many of these dresses. For sure it is great for work and depending on the accessories can change into a cocktail dress. I didn't give it 5 stars because I am not sure if it is just me but the cut around the dip in the neck is a little off and it keeps buckling. I have to adjust it but I mainly wear jackets over my dresses so it is not that bad.