OBJECTIVE: To examine factors associated with prostate-specific antigen (PSA) testing in the multiethnic California Men’s Health Study. STUDY DESIGN: Cross-Sectional analysis nested within a cohort of male health plan members (n = 55,278). METHODS: We extracted laboratory serum PSA values during the study period from 1998 to 2002. Using selected demographic and healthcare factors, we estimated the proportion of men who underwent PSA testing at least once during the 5-year period. Odds ratios and corresponding 95% confidence intervals were estimated to assess the association between these factors and PSA screening use. RESULTS: African American men had substantially higher PSA screening prevalence than white men (82.6% vs 73.7%). Low PSA screening use was associated with Latino race/ethnicity, lower level of education, residency in the United States for 25 years or less, current smoking, and lack of PSA test discussion with healthcare providers. The strongest positive predictors of PSA testing were African American race/ethnicity (odds ratio, 1.66; 95% confidence interval, 1.50-1.83) and high concern about prostate cancer (odds ratio, 1.53; 95% confidence interval, 1.38-1.69). In contrast, when men did not discuss PSA testing with their physicians, they were 80% less likely to undergo screening. CONCLUSIONS: In this insured population for whom financial barriers are minimized, PSA screening varied by race/ethnicity and by other patient and clinical factors, possibly reflecting inconsistencies in prostate cancer screening guidelines. Despite these differences, healthcare providers have a key role in patients’ likelihood of undergoing PSA screening.