In order to establish the actual recidivation rate, the patients with partial resections of the kidneys of the years 1965 to 1978 were examined. Of 120 patients treated 106 could be examined for the second time, at a mean time of secondary examination of 6.5 years. 24.5% of the patients had a recidivation at the time of the examination. The annual recidivation rate was calculated depending on the examination. It increases with the duration of the time of the after-examination. The comparison with the recidivation number after pyelolithotomy (26.7%) does not show an evident effect of the partial resection of the kidney on the frequency of recidivations. In the judgment, however, the selection of these patients for this operation technique is to be taken into consideration. The use of the coagulum pyelolithotomy has led to a more stringent indication for the partial resection of the kidney.