Bought this for a Titanic party. I am 5'3 and 130 lbs and the small fits me although it is a little tight around the shoulders since I do have slightly broader shoulders. I think the medium would be too big since the small fits me everywhere else. It also is a full length gown on me. The hem is to the floor but not dragging on the floor.  There is a zipper on one side of the dress. Very nice quality for the price.