The aim of this study was to report the clinical features, complications, abdominal sonographic findings, and treatment outcomes for a series of brucellosis cases in southern Turkey. This prospective study involved 251 patients (age range, 2-77 years) who were hospitalized with brucellosis during a 4-year period. Patients were classified as having acute (< 3 months), subacute (3-12 months), or chronic (> 12 months) disease. Physical, laboratory, and abdominal sonographic findings were analyzed. The disease was acute in 92 cases (36.7%), subacute in 48 (19.1%), and chronic in 111 (44.2%). Sonographic examination of the abdomen showed enlarged periportal lymph nodes in 23 patients (9.2%), splenomegaly in 21 (8.4%), hepatomegaly in 15 (6%), pleural effusion in 7 (2.8%), splenic abscesses in 4 (1.6%), splenic cysts in 2 (0.8%), acute appendicitis in 2 (0.8%), and acute acalculous cholecystitis in 1 patient (0.4%). The main hematologic and biochemical manifestations were anemia, elevated erythrocyte sedimentation rate, elevated C-reactive protein, and elevated transaminase levels. All patients were treated with combinations of either two or three antibiotics. Surgery was performed in the patients with acute appendicitis, acute cholecystitis, and multiple splenic cysts. Brucellosis is endemic to Turkey. Sonographic examination is the method of choice for diagnosing abdominal complications of human brucellosis. This disease should be included in the differential diagnosis for any patient with enlarged periportal lymph nodes. The specific treatment regimen and duration of therapy should be based on sites of organ involvement and complications.