Abdominal typhus is all the rearer disease among acute infectious diseases in Vojvodina. In the last ten years (1981-1990) 16 patients with abdominal typhus were treated at the Department of Infectious Diseases in Novi Sad, mostly young individuals from 6 to 30 years of age (13 patients). Positive epidemiologic features were found in 13 patients. In 80% of the cases the source of infection was outside Vojvodina. They usually were admitted at the Department on the first and second week of the disease (11 patients), and 3 patients were admitted on the third week. None of the patients was suspected of having abdominal typhus at the time of admittance. Delayed hospitalization and unrecognized abdominal typhus were most likely due to the atypical onset and course of the disease. Atypical features in the clinical picture occurred in all the patients with a sudden onset of the disease. The abrupt temperature elevation in 50% of the patients was followed by shivering, fever and shaking. Hepatosplenomegaly was found in 12 patients, abdominal meteorism in 10, typical typhus tongue in none. Typhus state was not found in any of the patients. Normal leucocyte count was found in 7 patients, positive Widal's agglutination reaction in 13, coproculture in 8 and hemoculture in 15 patients. The atypical clinical picture was the result of early administration of broad-spectrum antibiotics before the established etiology of the febrile state.