"I am a full 36C, 5' 4", 135 lbs. I got an XS and a S due to blouson style of top. I kept the XS. The small poofs out too much and gave a pumpkin look. I LOVE the elastic banding at waist, blouson style. The material was a very nice surprise- a bit of a sheen, shiny- I love that- it MADE the top. I am cutting off the ruffle that drapes down under the arm- it makes an otherwise simple, sweet, romantic top look too over-done and ruins the appeal. But, definitely size down if you are struggling to decide sizes. A full 36C chest, I rarely get XS- it's a tiny tad snug under my arm only, but otherwise fits beautifully and looks 100% nicer than the small did on me."