Since cefoxitin has been shown to be an effective alternative to spectinomycin for the treatment of infections due to penicillinase-producing strains of Neisseria gonorrhoeae (PPNG) its efficacy was compared with that of a new cephalosporin, ceftriaxone (R013-9904). One hundred and twenty eight men with culture-confirmed gonococcal urethritis were treated with either 250 mg of ceftriaxone intramuscularly or 2 g of cefoxitin intramuscularly with oral probenecid 1 g. The incidence of penicillin-resistant strains in each group was about 60%. Ceftriaxone was completely effective in treating both penicillin-sensitive and penicillin-resistant gonococcal urethritis. No side effects were noted. Ceftriaxone thus seems to be an effective and safe alternative to either spectinomycin or cefoxitin in the treatment of penicillin-resistant gonococcal urethritis.