PURPOSE We aimed to determine the effective dose given to patients during neuroradiological C-arm computed tomography (CT) procedures. MATERIALS AND METHODS Measurements were performed on 48 patients using dose-area, product (DAP) meter. A PC-based Monte Carlo program (PCXMC, STUK, Helsinki, Finland) was used to calculate the effective dose from the DAP values of each patient. Organ doses were also measured with thermoluminescent dosimeters (TLDs) using a human-shaped phantom. RESULTS The difference between the Organ doses measured using TLDs, and PCXMC was not significant (P > 0.05): The mean DAP for 48 patient was 9.41 +/- 2.50 Gy.cm(2); the mean effective dose for all procedures was 0.30 +/- 1.08 mSv. The coefficient for the correlation (R-2) between the DAP and the effective dose was 0.97. The conversion factor between the effective dose and DAP was 0.030-0.035 mSv.Gy(-1),cm(2). CONCLUSION DAP can be used as a dose indicator to calculate the organ dose and effective dose of patients based on Monte Carlo simulation. This method can provide important information on the absorbed dose and enhance the radiation protection of patients during C-arm CT procedures.