Kraus RD, et al. - Whether Surveillance, Epidemiology, and End Result Program (SEER) information on initial treatment of prostate cancer is valid was investigated by comparing it to electronic medical record (EMR) review. High sensitivity of the SEER data was observed. Moreover, the SEER data demonstrated a high positive prognostic ability in terms of surgery and radiation therapy, but underreported active surveillance use. Overall, these data may aid researchers in understanding the strengths and weaknesses of SEER prostate cancer treatment data.