I have a mustache and used to have problems with my cheap, entry-level mask. After switching to the ScubaPro Solo mask I rarely have any problems. The mask skirt is thinner and conforms to my face better. Every now and then I have problems, but certainly not on a regular basis. Also, I find it helps if my mustache is thicker and overlaps opposed to having a thinly trimmed mustache. I hope this helps.