Background.- Syphilis is a chronic, multisystem infectious disease caused by spirochete Treponema pallidum. It is often transmitted by sexual contact and lasts in graded stages. Skin lesions are predominant in primary and secondary stages. Hepatitis and fever are rare in secondary syphilis. Diagnosis is made by treponemal and non-treponemal tests. Penicillin is the first choice in patients who are not allergic to this drug. Observation.-A 26 years old, single, male patient with syphilis having fever and abnormal liver func¬tion tests is presented. The diagnosis of syphilis was made by RPR and TPHA tests. After initiation of peni¬cillin therapy, the fever disappeared and the liver function tests became normal. Conclusion.- Syphilis should be considered in the differential diagnosis of unexplained liver enzyme abnormalities and fever.