The mobility of our society may play an important part in the epidemic proportions of sexually transmitter diseases in the United States. Chancroid, one of the major venereal diseases, is caused by Hemophilus ducreyi and can be recognized clinically. Because the morbidity of chancroid is related to delay in treatment, awareness of this disease is mandatory. Definitive laboratory proof can be obtained in only 50 percent of the cases. Sulfisoxazole is the drug of choice.