Background: Tuberculous (TB) pericarditis is a major cause of constrictive pericarditis warranting pericardiectomy. Initial prognostic predictors in these patients have not been clearly elucidated. Methods: In 60 patients diagnosed as acute TB pericarditis, initial presentations and clinical outcomes were evaluated for 32짹27 months with adequate anti-TB medications for ���6 months. Results: Initial presentations were pericardial effusion (PE), effusive-constrictive pericarditis and constrictive pericarditis in 45(75%), 9(15%), and 6(10%) patients, respectively. Of 54 patients except initial constrictive pericarditis, 32 patients(59%) showed echogenic materials in PE, including frond-like exudative coating and fibrinous strands (Fig.A). Those patients were initially more symptomatic, in more advanced state, ended up more with persistent pericardial constriction (38% vs. 0%, p<0.001) despite anti-TB medications, and tended to undergo pericardiectomy more (19% vs. 0%, p=0.07, p<0.05 by Kaplan-Meier, Fig.B) than others. All patients with effusive-constrictive pericarditis showed echogenic PE. Of a total of 60 patients, 10 patients(17%) underwent pericardiectomy during the follow-up. All of those 10 patients showed initial pericardial constriction, while no one without initial pericardial constriction underwent pericardiectomy (p<0.001, Fig.C). Conclusions: Initial pericardial constriction and echogenic PE seem to be poor prognostic signs predicting persistent pericardial constriction and pericardiectomy in patients with acute TB pericarditis.