I'm an XXL guy, on the bigger size. I wear a size 40 pants and XXL shirts with room, XXL is usually a little baggy. This vest, even in XXL would NOT fit. When they say it's a slim fit, they really mean slim, but I purchased this vest for a wedding (groomsman, so I had no other option) and I had to take it a local seamstress to add approx. 4" to each side for it to fit. So, make sure to pay attention to the size guide and measure! Aside from that, VERY high quality, I loved it.See full review