I tried on the xs in the store, and i don't need a petite in this, but perhaps a xxs. it is on the shorter side, so no great on my muscular thighs (if petite) whereas the regular size hit me just above the knee. the cut is away from the body, a bit "a-line", but not fitted. the colors are gorgeous, but i think this is more of a casual dress, like brunch with the girlfriends, for example. love it... it is now in my wish list for alter :-)