Background: Endoscopic retrograde cholangiopancreatography (ERCP) is now widely used in the diagnosis and treatment of gastrointestinal tract disorders. A large number of X-ray fluoroscopy and digital radiographs make ERCP as an interventional radiological procedure. In this study, patients' and examiner's entrance skin doses (ESDs) were measured during diagnosis and treatment procedures and patients' effective dose (ED) were calculated. Materials and Methods: Thermoluminescent dosimeters (TLDs) and dose area product meter (DAP) were used to measure ESDs of 30 patients and examiner and calculate patients' ED. Besides, to assess the effectiveness of an extra lead shield in decreasing examiner's ESDs, a lead cover was wrapped around the X-ray tube. The data were analyzed with IBM SPSS Statistics version 16 software. Results: The mean DAP and fluoroscopy time (FT) of the diagnostic procedure were 4.09 Gy.cm² and 32.4 s while those of the therapeutic procedure were 7.60 Gy.cm² and 76.2 s. The strong linear correlation between DAP and FT was observed for the therapeutic procedures but the diagnostic ones. The patients' mean EDs of diagnostic procedure (1.21±0.52 mSv) and therapeutic one (2.25±1.72 mSv) were calculated. Moreover, the shielding cover around the X-ray tube decreased ESDs of the organs of interest except gonads. Conclusions: The results reveal that therapeutic ERCP procedure imposes a greater radiation dose compared to diagnostic ERCP one. However, the doses of the patient and the examiner depend highly on examiner's experience, technical skills and knowledge in radiation protection. The results suggest that attempts to reduce radiation doses should be made.