This study investigated prostate cancer screening practices using prostate specific antigen testing (PSA), digital rectal examination (DRE), and transrectal ultrasonography (TRUS) by primary care physicians in Missouri. In 1993, a mail survey was sent to a stratified random sample of 750 physicians whose primary specialty was general practice, family practice, or internal medicine. Three separate mailings resulted in an overall adjusted response rate of 60 percent. Ninety-five percent of physicians were more inclined to use PSA compared with three years previously, with only 45 percent of physicians more inclined to use DRE. An increase in the use of PSA following a negative DRE was reported by 85 percent and a greater inclination to use TRUS following a positive PSA was reported by 90 percent Eighty-six percent agreed with the American Cancer Society (ACS) guidelines on prostate cancer screening. Using logistic regression adjusted across levels of demographic and practice factors, prevalence odds ratios were derived with results indicating that agreement with ACS guidelines and being in private practice are strong predictors of a physician's inclination to routinely screen asymptomatic patients for prostate cancer. Our findings have provided baseline information on prostate cancer screening in Missouri and suggest that primary care physicians view PSA testing as a useful procedure and appear to be using it in a manner similar to the general pattern seen across the country.