We aimed to assess the effectiveness of subxiphoid pericardiostomy for treating patients with pericardial effusions (PE), and its contribution to defining the aetiology of these effusions. We undertook retrospective analysis of 240 PE patients who underwent subxiphoid pericardiostomy and tube drainage between 1990 and 2000. Echocardiography classified PE as severe in 132 patients, moderate in 99, and mild in nine. The main causes of PE were uraemic, idiopathic and undefined, tuberculous and non-tuberculous pericarditis, malignancy and trauma. Peri-operative myocardial injury requiring sternotomy, and recurrent effusion requiring further surgical intervention, occurred in three and 24 patients, respectively. Histopathological examination assisted the diagnosis in 94% of patients with malignancy, and 96% with tuberculous pericarditis. Overall 30-day mortality was 1.3% and pericardial constriction, requiring pericardiectomy, developed in seven cases. In conclusion, we believe that adults and children with PE can be safely, effectively and quickly managed with subxiphoid pericardiostomy, irrespective of its aetiology.