We investigated prolidase activity in samples derived from wound fluid as well as blister fluid. Prolidase activity was elevated in fluid samples collected from wounds over the levels in sera collected from patients with chronic wounds (P < 0.05). Prolidase activity was also present in samples taken from blister diseases. However, prolidase activity in blister fluid was not higher than that in sera collected from patients with blister diseases. Our results indicate that prolidase may play a role in wound healing.