One hundred seventy-five patients with primary infection with Treponema pallidum were treated with benzathine penicillin G, 2.4 million units given intramuscularly weekly for two weeks for a total of 4.8 million units. Twenty-one patients with primary syphilis who were allergic to penicillin were treated with oral tetracycline, 500 mg four times daily for 12 days for a total of 24 gm. All 196 patients had resolution of their lesions, and all were seronegative within one year. White patients presented for treatment earlier than black patients. The duration of symptoms prior to presentation for treatment was positively correlated with the height of the serologic titer in the rapid plasma reagin card test. Patients who had high titers before treatment became seronegative less rapidly than patients who had low pretreatment titers.