Abstract Objective: To provide an updated assessment of the influence transurethral resection of the prostate (TURP) has on incidental detection of prostate cancer and to characterize stage, histologic grade, and treatment patterns among these cases. Methods: Analyses were based on 17,310 histologically confirmed prostate cancer cases ages 45 years and older recorded in the Utah Cancer Registry between 1980 and 1999 and 6426 TURP procedures recorded in the Utah Hospital Discharge Database from 1992 through 1999. An algorithm was developed for identifying TURP-detected prostate cancer incidence. Results: Age-specific TURP-detected prostate cancer incidence rates tended to be flat between 1980 and 1990, decline through 1994, and then level off. Much of the decrease corresponds to the prostate-specific antigen (PSA) screening induced peak and subsequent fall in total prostate cancer incidence rates. Leveling off in the TURP-detected rates between 1994 and 1999 corresponds with a leveling off in the total prostate cancer incidence rates. The percentage of prostate cancer detected by TURP significantly increases with age, within each age group, but decreases over calendar years. For ages 45 years and older, the percentage of TURP-detected cases was 39.0% in 1980 to 1984, 33.9% in 1985 to 1989, 12.2% in 1990 to 1994, and 7.4% in 1995 to 1999. TURP-detected cases were significantly less likely to undergo radical prostatectomy or radiation therapy across age groups, despite having lower stage and histologic grade at diagnosis. Conclusion: TURP-detected prostate cancer rates have leveled off in the latter part of the 1990s, explaining about 10% of all detected cases. These cases have relatively good biologic potential and are less likely to pursue aggressive therapy.