A total of 678 cases of soft chancre were treated in one hospital between 1973 and 1979. The majority of the patients were males (97 p. cent), and most of them came originally from Maghreb or Black Africa. Contamination was from prostitution (61 p. cent) or chance acquaintances (29 p. cent). The genital ulceration was often clinically atypical, frequently syphiloid; pain was present in only 59 p. cent of cases, and adenopathy, noted in 63 p. cent of patients, had the appearance of an inflammatory bubo in only 23 p. cent. The present high frequency of soft chancres, and their misleading clinical characteristics, makes it sometimes difficult to establish the clinical differential diagnosis from syphilitic chancre, but confirmation of the latter is supplied by direct examination and culture to search for Ducreys bacillus, this being indispensable for establishing the correct diagnosis. Treatment with sulfamethoxazole trimethopin or streptomycin prevents complications and cures the affection in one or two weeks.