Definitely runs a little big.  I normally wear a 1 or 2x in women's clothing, and this shirt was big on me.  Especially in length and in the shoulders.  But that's ok, my husband is very tall and it's now his for our upcoming Jimmy Buffet party.  Great looking shirt for men or women, very vivid colors, really cool & fun details.  Good price and very prompt delivery.  Would definitely recommend to others.  Still on the lookout for a shirt for me though.