PURPOSE: Diagnosis of advanced prostate cancer is a major health problem, especially among low-income men. Opportunities vary for early detection of prostate cancer for low-income black and white men because of financial, cultural, and social factors. In this study, we evaluated the association of poor literacy skills with higher rates of presentation of advanced stages of prostate cancer among low-income black and white men who received care in equal-access medical systems. PATIENTS AND METHODS: Literacy and stage at diagnosis of prostate cancer were evaluated in 212 low-income men who received medical care in Shreveport, LA, and Chicago, IL. The patients' literacy was assessed with the Rapid Estimate of Adult Literacy in Medicine (REALM), an individually administered reading screening test designed specifically for use in the medical setting. Logistic regression models were used to evaluate predictors of metastatic disease at presentation as a function of patient age, race, literacy, and city. RESULTS: Whereas black men were almost twice as likely to present with stage D prostate cancer (49.5% v 35.9%; P < .05), they were significantly more likely to have literacy levels less than sixth grade (52.3% v 8.7%; P < .001). However, after adjustment for differences in literacy, age, and city, race was not a significant predictor of advanced-stage prostate cancer. CONCLUSION: Low literacy may be an overlooked but significant barrier to the diagnosis of early-stage prostate cancer among low-income white and black men. The development of culturally sensitive, low-literacy educational materials may improve patient awareness of prostate cancer and improve the frequency of diagnosis of early-stage cancer.