The purpose of this investigation was to evaluate the effect of wearing a wet suit on selected psychological and physiologic variables. Certified divers (n = 13) finned underwater at 0.52 m/s for 20 min with and without a wet suit. Order was randomly assigned and performed on separate days. Heart rate, respiration rate, use of compressed air, ratings of perceived exertion, and breathing ratings increased significantly (P < 0.05) for both conditions, and increases in heart rate, use of compressed air, and breathing ratings were significantly greater for the wet-suit condition. Rectal temperature increased significantly (P < 0.001) for the wet-suit but not the bathing-suit condition. State anxiety and body awareness increased (P < 0.001) following the wet-suit condition. Furthermore, state anxiety decreased significantly (P < 0.001) by 15 min after exercise in the bathing-suit condition. It is concluded that wet suit wear can result in elevated anxiety when performed at a water temperature and exercise intensity sufficient to produce increased core temperature.