To evaluate and compare the dimension of radiation exposure in diagnostic radiology new diagnostic reference levels, acccording to the patient directive EURATOM 97/43, were established throughout europe. As suitable indicator for radiation exposure the dose area product was recommended. With the aid of a skull phantom the influence of variation of technical parameters (tube voltage, filtering, collimation) on the dose area product was analysed, using two different x-ray machines (image intensifier, flat panel detector). Using different x-ray film cartridge sizes a dose reduction between 21,05% and 38,84% could be achieved through the raise of tube voltage. A raise of filtering from 0,1mm to 0,3mm copper lead to a procentual reduction of dose area product between 29,64% and 35,30%. Organ suited collimation achieved dose reduction up to 53,25%. The comparison of both x-ray machines showed no significant difference concerning radiation exposure. In the second part of this dissertation radiographs of the chest organs in two levels were examined. On a group of 41 patients (24 male, 17 female) it could be confirmed that the current valid diagnostic reference values were observed through out all explored examinations. The collected dose values thereby were subject to a considerable range of variation. In addition the effect of anthropometric attributes (age, sex, body height and weight, body mass index, patient diameter) on the development of dose area product was analysed. Whereas body mass index, body weight and patient diameter correlated significantly with radiation exposure in radiologic examinations of the chest organs, age and body height seemed to have no influence on the radiation dose. The comparison of both sexes just showed little differences in the ranking of the variables body mass index and body weight in relation to the correlation with the measured radiation dose.