I just bought this nice dress on sale as i love the dolan brand and purchased my regular size small (34/27/35) and it fits me perfect so i'd say it runs tts. the material is nice and soft, not see through at all and a good length (i'm 5'4"). i bought the regular and didn't seem to need a petite. it's a slimming dress that's not overly tight too. i also really like the mock neck and don't find it constricting at all as the material has a bit of stretch. the short sleeves will be nice when it's sp