Background and Objectives: Pericardial effusion (PE) is frequently found in patients infected with the human immunodeficiency virus (HIV), but its clinical significance remains unclear. Our purpose was to study the manifestations of HIV-infected patients with PE and the coexistence of these manifestations with other echocardiographic abnormalities, compared with patients without PE. Methods: We reviewed 141 HIV-infected patients in whom echocardiographic study was performed. We studied their epidemiological, clinical, hematological, immunological, electrocardiographic (ECG) and echocardiographic characteristics and their in-hospital outcome. Results: Patients with PE (n = 55), compared with those without PE (n = 86), were more often clinical stage C and immunological stage 3, had left-ventricular dysfunction and right-ventricular dilatation more frequently, and had been diagnosed as HIV-positive for a longer time. Seven patients with moderate to severe PE developed cardiac tamponade. Compared with patients with small PE (n = 34), those with moderate to large PE (n = 21), had pericardial rub, ECG repolarization abnormalities consistent with pericarditis, immunological stage 3, left-ventricular dysfunction and right-ventricular dilatation more frequently. In 3 patients, cardiac tamponade disappeared after anti-tuberculous therapy; in 3 cases, pericardial drainage was performed (anti-tuberculous therapy was not attempted); 1 patient with cardiac tamponade was not drainaged because he was a terminal patient with an extensive lymphoma. Conclusions: PE in HIV-infected patients is associated with (1) advanced stages of infection, and (2) left-ventricular dysfunction and right-ventricular dilatation; (3) presence of pericardial rub and ECG alterations consistent with pericarditis suggests the existence of moderate to large PE.