Study objective: The most common extraintestinal manifestation of Entamoeba histolytica , the agent of amebiasis, is a hepatic abscess. This infection is common throughout the world and can be associated with life-threatening consequences. Given the often nonspecific nature of the complaints related to an amebic abscess, a retrospective review of patients with confirmed disease was done to recognize the most common patterns of presentation. Methods: A retrospective case series was conducted of all patients with confirmed amebic liver abscess over a 5-year period. All available emergency department and inpatient records were reviewed. Age, sex, country of origin, chief complaint (including duration), vital signs, and physical and laboratory findings were recorded. The use of ultrasonography, computed tomography scan, chest radiograph, and serum antibodies was noted, as well as the final ED diagnosis. Results: Seventy-five patients were reviewed; mean patient age was 35.5 years, 80% were male, and Mexico was the country of origin for 64%. The most common complaint was fever (77%), followed by abdominal pain (72%), which was most often located in the right upper quadrant. Cough (16%), chest pain (19%), and chest radiographic abnormalities (57%) were also common. The majority of patients (69%) had symptoms for less than 13 days. The WBC count was the most consistent laboratory abnormality (83%), whereas the liver aminotransferase, alkaline phosphatase, and bilirubin levels were often normal. Most patients received their diagnoses on the basis of ultrasonography (85%), followed by a confirmatory serum antibody titer (88%). The diagnosis of amebic liver abscess was correctly made in the ED in 31.5% of the patients, with the most common misdiagnoses being cholecystitis (16.4%), hepatitis (12.3%), and pneumonia (9.6%). Conclusion: Patients with amebic liver abscess do present to EDs in the southwestern United States, especially in areas with a high immigrant population from endemic areas. Patients with complaints of fever and right upper quadrant abdominal pain, especially men of Hispanic origin, warrant a high degree of vigilance. Whereas most laboratory studies are unhelpful, the diagnosis can often be made in the ED by means of a bedside ultrasonographic test. Treatment should be initiated with metronidazole with disposition to an inpatient medical service. [Hoffner RJ, Kilaghbian T, Esekogwu VI, Henderson SO: Common presentations of amebic liver abscess. Ann Emerg Med September 1999;34:351-355.]