Depends on what size you're -- this is the "Pigalle 100" (4-inch Pigalle) pump, with sculpted heel. I'd say that for the smaller sizes (38 and below), it's pretty much true to size. For larger sizes it may depend on the width of your foot; if you have wide feet (for CL shoes), then certainly size up. Personally I found the "Pigalle 100" with sculpted heel (especially the patent version) to be very much true-to-size; for "Pigalle 120" I had to size up 1/2 a size to a full size from my "Pigalle 100" size as the higher 120mm heel means the foot is prone to sliding forward a lot more.