During 1989-90 the Australian Radiation Laboratory conducted a postal survey of at least 90% of the mammographic facilities in Australia. The primary aim of the survey was to measure the mean glandular dose (MGD) and the X-ray beam half value layer (HVL) for a typical mammograph. The MGD and HVL were measured with a specially designed tissue equivalent monitor. In all, 258 mammographic centres were surveyed. It was found that for centres using film-screen imaging, the average mean glandular dose was 1.83 mGy for centres using grids and 0.84 mGy for centres not using grids. In addition to the MGD and HVL, comprehensive statistical information was collected and data is presented on the types of equipment and techniques used, the number and age of patients and demographic distribution of centres. Results indicate that the use of a grid is the major factor determining dose and several other factors appear to have minor effects. In view of the distribution of MGD, it is recommended that the mean glandular dose per image, for a 5 cm compressed breast thickness, should not exceed 2.0 mGy when a grid is used and 1.0 mGy without a grid. 63 refs., 11 tabs., 15 figs.