[en] From information relating to numbers of various types of diagnostic medical X-ray procedures annually performed over the period 1962-1981 and mean radiation doses thereby delivered to various organs, estimates were derived of mean annual effective dose equivalents to the Bulgarian population; they were found to have risen from 0.5 msv per capita for 1962 to 1.35 msv per capita for 1981. Also, taking into account information on population age distributions, genetically and leukemogenically significant doses were calculated and found to have increased from 0.3 and 0.45 msv per capita for 1962 to 0.96 and 1.15 msv per capita for 1981, respectively. Analysis of collective gonad dose equivalents for 1981 indicated medical applications and diagnostic X-rays in particular to be responsible for the bulk radiation exposure in excess of background. As of 1981, the absolute level of risk incurred through radiological diagnosis was estimated at 240 lethal cases (146 fatal malignant tumors and leukoses, and 94 severe genetic effects). The death rate from malignancies for this period being of the order of 13.5 x 10³ cases, the additional 146 cases constitute less than 1% of spontaneous deaths. (authors)