Our objective was to examine the outcomes of patients with left ventricular (LV) dysfunction who underwent operation for Ebstein anomaly. From April 1, 1972 to January 1, 2006, 539 patients with Ebstein anomaly underwent operation at Mayo Clinic. LV function was determined by echocardiography. Of the 495 patients with preoperative echocardiographic assessment of LV function, 50 had moderate or severe LV systolic dysfunction. In patients with LV dysfunction, the tricuspid valve (TV) was repaired in 12 patients and replaced in 36 patients; 1 patient had a 1.5 ventricle repair, and 1 patient had cardiac transplantation. There were 5 early deaths (10%). LV function improved in all but 4 patients after operation. In no patient did LV function worsen after operation. The 1-, 5-, and 10-year survival was 86%, 77%, and 67%, respectively. On univariate analysis, absence of sinus rhythm at dismissal (p = 0.003) was associated with greater overall mortality. For the entire cohort of 539 patients, LV dysfunction was independently predictive of late mortality (hazard ratio 3.76, p <0.001). At late follow-up (mean 6.9 years), 86% of patients were in New York Heart Association class I or II. In conclusion, LV systolic dysfunction occurs infrequently in patients with Ebstein anomaly and is a risk factor for increased late mortality. Although early mortality is greater in patients with LV dysfunction, the late results are favorable. Decreasing LV function should be an indication to promptly restore TV competence rather than a contraindication to TV operation.