Effective dose ( E ), representing the risk of late radiation-induced effects, can be estimated by the use of conversion factors (CF), converting direct measurable quantities such as dose-area-product into E . Eight Belgian hospitals participated in the study with a total number of 318 procedures. E -values, calculated with PCXMC, were compared for the different hospitals for diagnostic and therapeutic procedures separately. E -values varied significantly depending on the hospital where the procedure was performed ( P < 0.001), on filtration insertion ( P < 0.001), on whether a centre is a training centre or not, the dose conscious action of the cardiologists and the complexity of the procedure ( P < 0.001). Hospital-specific CF were calculated. An average CF of 0.185 mSv Gycm−2 was obtained with a satisfactory correlation ( r = 0.966, P < 0.001). The differences in CF between hospitals were due to, a large extent, the availability of additional filtration in cinegraphy mode ( P < 0.001) and not to the differences in irradiation geometries in the clinical protocol of the interventional procedures.