This observational study was conducted owing to the challenges of the positron emission tomography/magnetic resonance imaging (PET/MRI) that requires longer duration scanning of radiopharmaceutical injected patient and added MRI environment. The aim of this study was to assess radiation dose at different distances from the patient and the radiation burden to anesthesiologist and other personnel in performing PET/MRI under general anesthesia or sedation. First, the pre- and postscan whole body radiation exposure (WBE) from the patient were obtained for 45 minutes (n = 109) after injection of the radiopharmaceutical. The WBE was obtained at specific distances from brain (10, 30, and 100 cm) and abdomen (10 and 30cm) of patients undergoing F18 fluorodeoxyglucose PET/MRI brain or whole body studies. Second, WBE of the anesthesiologist and other staff working was separately measured using pocket dosimeters during the whole procedure. In brain scans, the mean absorbed dose rates (ADR) of prescan (45 minutes) and postscan (45 minutes) were 44.4 and 31.1 μSv at 10 cm, 14.9 and 9.7μSv at 30 cm, and 3.5 and 2.8 μSv at 100 cm, respectively, from surface of head. Similarly, it was 54.8 and 30.3 μSv at 10 cm, 23 and 13.6μSv at 30 cm, respectively, from surface of abdomen. In WB scans, the mean ADR was higher than the brain scans. Anesthesiologist exposure overall was found to be 4.84 µSv/patient/scan (112 patients). The anesthesiologist receives a safe mean effective dose in PET/MRI scanning. With good training and adequate planning, it is possible to decrease the radiation exposure to all the concerned personnel including anesthesiologists.