This review article provides an overview on the results of studies conducted by the authors to improve the current personal protection concept in the clinical application of x-rays. With the aid of personal dose equivalent measurements during radiologically guided clinical interventions, laboratory tests using the Alderson-Rando phantom as well as Monte Carlo simulations various x-ray application scenarios were investigated. The organ doses and the effective doses of staff persons standing near the patient were determined. The 3D-attenuation properties of protective clothing under the scattered radiation emitted by the patient play a special role here. With regard to the minimisation of the quantity 'effective dose' the protection of the lower body from the gonads to the chest is of particular importance, since 80% of the effective dose is contributed by this region of the body. In contrast, protection of the back plays a subordinate role. Protective aprons optimised in terms of effective dose can be significantly lighter than conventional aprons, providing equal protection. The assessment of the attenuation properties of protective clothing should be based on the risk-related dose quantity, effective dose, rather than lead equivalent. In the future, the evaluation of radiation protective clothing could be based on the calculation of the effective dose assuming standardised irradiation conditions.