Background: Cardiac conduction abnormalities have been associated with infection extension and mortality in infective endocarditis (IE). However, there has been no long-term study of conduction abnormalities in patients with IE. The aim of this study was to evaluate the in-hospital and long-term clinical outcome in patients with IE according to electrocardiogram (ECG) pattern. Methods: Eighty-two consecutive IE patients with interpretable ECG between July, 2002 and June, 2008 were included. Mean follow-up months was 21 짹 23. IE was defined as ���Definite��� or ���Possible��� by the Modified Duke criteria. ECGs were examined for the presence of conduction abnormalities. Invasive infection was defined by the presence of an abscess or paravalvular leakage. Results: Conduction abnormalities were present in 27 (33%) patients. Patients with conduction abnormalities met more often ���Definite��� Modified Duke criteria (82% vs 55%, P=.017), and invasive infection (37% vs 11%, P=.005). There were no significant differences in microbiology results or frequencies of vegetation. Patients with conduction abnormalities had more often in-hospital embolic events (63% vs 29%, P=.003), in-hospital composite events (63% vs 33%, P=.009), long-term follow-up total death (33% vs 13%, P=.027), and long-term follow-up composite events (78% vs 35%, P<.001). However, there was no significant difference of in-hospital death between two groups (19% vs 7%, P=.147). In Multivariate analysis, the presence of conduction abnormalities was an independent predictor of in-hospital embolic events (Odds ratio (OR)=4.27, P=.043). In Kaplan Meier method, patients with conduction abnormalities showed worse long-term follow-up death and worse long-term follow-up composite events (P=.029, P<.001, respectively). In Multivariate analysis, the presence of conduction abnormalities was also an independent predictor of long-term follow-up composite events (OR=24.39, P<.001). Conclusion: Conduction abnormalities are associated with invasive infection, increased mortality and increased embolic events. The presence of conduction abnormalities was a useful predictor of embolic and total composite events during admission as well as during long-term follow-up periods.