This study explored their work characteristics and safety compliance to identify primary factors influencing high occupational radiation exposure among radiologic technologists. A total of 12 387 radiologic technologists were surveyed from 2012 to 2013 in South Korea. Survey data for demographics and work-related characteristics were linked with the National Dose Registry. Multiple regression analysis was used and '% Excess Risk Explained' was calculated to illustrate the degree to which given risk factors explained the relationship of work procedures and radiation exposure. Characteristics of radiologic technologists exposed to higher radiation doses were male, aged <30, working at a general hospital or hospital, and frequently performing routine diagnostic X-ray, CT, portable X-ray and C-arm. Not being completely separated from patients and wearing lead apron was positively associated with higher radiation exposure. Type of facility and safety compliance were the main risk factors for high radiation exposure in performing diagnostic radiologic procedures.