BACKGROUND: Racial and ethnic minorities are under-represented in clinical trials of primary prevention implantable cardioverter-defibrillators (ICDs). This analysis investigates the association between primary prevention ICDs and mortality among Medicare, racial/ethnic minority patients. METHODS AND RESULTS: Data from Get With The Guidelines-Heart Failure Registry and National Cardiovascular Data Registry's ICD Registry were used to perform an adjusted comparative effectiveness analysis of primary prevention ICDs in Medicare, racial/ethnic minority patients (nonwhite race or Hispanic ethnicity). Mortality data were obtained from the Medicare denominator file. The relationship of ICD with survival was compared between minority and white non-Hispanic patients. Our analysis included 852 minority patients, 426 ICD and 426 matched non-ICD patients, and 2070 white non-Hispanic patients (1035 ICD and 1035 matched non-ICD patients). Median follow-up was 3.1 years. Median age was 73 years, and median ejection fraction was 23%. Adjusted 3-year mortality rates for minority ICD and non-ICD patients were 44.9% (95% confidence interval [CI], 44.2%-45.7%) and 54.3% (95% CI, 53.4%-55.1%), respectively (adjusted hazard ratio, 0.79; 95% CI, 0.63-0.98; P=0.034). White non-Hispanic patients receiving an ICD had lower adjusted 3-year mortality rates of 47.8% (95% CI, 47.3%-48.3%) compared with 57.3% (95% CI, 56.8%-57.9%) for those with no ICD (adjusted hazard ratio, 0.75; 95% CI, 0.67%-0.83%; P<0.0001). There was no significant interaction between race/ethnicity and lower mortality risk with ICD (P=0.70). CONCLUSIONS: Primary prevention ICDs are associated with lower mortality in nonwhite and Hispanic patients, similar to that seen in white, non-Hispanic patients. These data support a similar approach to ICD patient selection, regardless of race or ethnicity.