The overall incidence in gonorrhoea of septic gonococcal dermatitis was found to be 1.9% (3% for the females and 0.7% for the males). In 23 patients the common presenting symptoms were arthritis or arthralgia and bouts of fever, but the characteristic skin lesions served as an early clue to the diagnosis, and Neisseria gonorrhoeae was isolated from the genitourinary tract or from the blood. With the use of immunofluorescent techniques gonococci were also found in smears prepared from the skin lesions. An immune response to gonococci was found with the complement fixation technique in 90% of the patients. The response to treatment with penicillin was prompt, with complete relief from joint pains and fever, usually within two to seven days. The skin lesions faded within a few days, but scars could be observed for up to four weeks.