Objective: Because appropriate rectal cancer care and subsequent outcomes can be influenced by several variables, our objective was to investigate how race, ethnicity, and socioeconomic status (SES) may impact rectal cancer outcomes. Background: The management of rectal cancer requires a multidisciplinary approach utilizing medical and surgical subspecialties. Methods: We performed an investigation of Patients with rectal adenocarcinoma from Los Angeles County from 1988 to 2006 using the Los Angeles County Cancer Surveillance Program. Clinical and pathologic characteristics were compared among groups and overall survival was stratified by race/ethnicity and SES. Results: Of 9504 Patients with rectal cancer, 53% (n=4999)werewhite, 10% black, 18% Hispanic, and 14% Asian. Stratified by race/ethnicity, Asians had the best overall survival followed by Hispanics, whites, and blacks (median survival 7.7 vs. 5.7, 5.5, and 3.4 years, respectively; P < 0.001). Stratified by SES group, the highest group had the best overall survival followed by middle and lowest groups (median survival 8.4 vs. 5.1 and 3.8 years, respectively, P < 0.001). Similar results were observed for surgical Patients. On multivariate analysis, race/ethnicity, and SES remained independent predictors of overall survival in Patients with rectal adenocarcinoma. Furthermore, interaction analysis indicated that the improved survival for select racial/ethnic groups was not dependent on SES classification. Conclusions: Within the diverse Los Angeles County population, both race/ethnicity, and SES result in inequities in rectal cancer outcomes. Although SES may directly impact outcomes via access to care, the reasons for the association between race/ethnicity and outcomes remain uncertain. © 2011 Lippincott Williams & Wilkins.