Background: Black men with breast cancer have more concomitant disease and worse survival than white men. Less is known about concomitant disease and survival in Hispanic and Asian/Pacific Islander (API) men with breast cancer. The purpose of this study was to compare differences in survival and risk of mortality of white, black, Hispanic, and Asian/Pacific Islander (API) men with breast cancer with increasing comorbidity. Methods: We identified 1,497 cases of first primary male invasive breast cancer from the California Cancer Registry 2000-2015 with a documented Charlson Comorbidity Index (CCI). The CCI is a weighted index based on the presence of certain comorbid conditions following a cancer diagnosis and weighted by the severity of these conditions. A score of 0 indicates no significant comorbidity and scores of 2 or more are interpreted as a high comorbidity burden. Bivariate associations between race and AJCC stage, tumor grade, estrogen receptor (ER) status, human epidermal growth factor 2 (HER2), and socioeconomic status (SES) were compared using the χ² Test of Independence. Kaplan Meier Survival analysis was used to compare unadjusted survival among the races. Cox Regression was used to assess risk of mortality for each race when adjusted for factors that had a statistically significant (p < 0.10) bivariate association with race/ethnicity. Analyses were conducted within each level of the CCI (0, 1, and 2 or more). Results: Among men with a CCI of 0 or 2, blacks had worse unadjusted survival than whites. There were no differences in survival for men with a CCI of 1. Stage, SES, ER, and type of surgery all had statistically significant bivariate associations with race/ethnicity. For men with a CCI of 0, Hispanics (HR = 0.367; 95% CI = 0.167, 0.801) and APIs (HR = 0.422; 95% CI = 0.189, 0.941) had a reduced risk of mortality when compared with whites. Black men had the same risk of mortality as white men. There were no differences in risk of mortality by race for men with a CCI of 1 or 2. Conclusions: Black men with breast cancer and no comorbidity have the same risk of mortality as white men while Hispanic and API men have lower risk of mortality. There are no racial disparities in adjusted risk of mortality in men with breast cancer with any concomitant disease.