The bacterium Aeromonas hydrophila is commonly found in natural bodies of water, and is a potential invasive pathogen for those who suffer trauma while submerged in water. Five patients treated by the authors and 18 previously reported patients were reviewed to further define the characteristics of A. hydrophila wound infections. Although Aeromonas has been isolated from salt and brackish water, all 23 cases occurred following contact with fresh water. Signs of infection usually appeared 8-48 hours following puncture or laceration injury. The foot or leg were most commonly involved. Infection was frequently rapidly progressive; fascia, tendon, muscle, bone, or joint involvement occurred in 39% of cases. In addition to A. hydrophila, other aerobic and anaerobic bacteria were found in 48% of cases. Aeromonas infection should be suspected in cases of early and rapidly progressive wound infection following trauma in fresh water. Broad-spectrum antimicrobial therapy and appropriate surgical care should be promptly instituted.