A double-blind prospective study of 98 patients was carried out, but 57 (58%) returned for follow-up and form the basis of this report. Wound irrigation and debridement were found to be important in reducing infection. Hand wounds were most likely to become infected; face and scalp wounds were at low risk. Puncture wounds became infected more often than did lacerations. Suturing wounds did not increase the likelihood of infection except on the hand, where the data were equivocal. Prophylactic penicillin decreased the incidence of infection in high-risk wounds; there was no difference in low-risk wounds. Cultures of wounds showed many different organisms but were of no predictive value. Pasteurella multocida was found very rarely. Staphylococcus aureus accounted for 10% of all infections, a finding which makes use of a penicillinase-resistant penicillin logical.