I'm not a runner, but I have very tiny and sensitive feet. I have a hard time finding decent tennis shoes in my size. I usually wear a children's 2:women's 4. So, all the tennis shoes I get are in children's sizes and they SUCK! I read reviews that these shoes ran small, so I decided to give them a try. I ordered the  women's 5 and they fit perfectly (my only pair of women's tennis shoes and I'm 23). So, like everyone else, yes they do run a size, to a size and a half small! But, they are very comfortable and look great! I would recommend them!