Abstract: A surgical instrument includes a hollow handle having an end slot and a side slot and a blade carrier securable to a scalpel blade and moveable between first and second positions relative to the handle. One of the first and second positions is an extended, in-use position wherein the scalpel blade extends out of the handle through the end slot. The other position is a retracted, non-use position wherein the scalpel blade is wholly disposed within the handle. At least one finger extends from the blade carrier and has a first contoured portion engageable, when the blade carrier is in the first position, with a second contoured portion of the handle. The first and second contoured portions are substantially complementary such that the finger must deflect to permit disengagement of the first contoured portion of the finger from the second contoured portion of the handle so that the blade carrier can be moved from the first position toward the second position.