The histopathologic follow-up of local tumor regression of prostatic cancer under hormonal treatment or following high-voltage therapy is an objective standard to determine a therapeutic success. This report involves 308 patients, who were continuously controlled by serial biopsies, 1,138 punch biopsies, and 155 TURs from 1971 to 1981. On an average, there are 4.2 biopsies of each patient. The patients were treated with estradiol. They were divided into two groups by histologic classification: 1) adenocarcinomas with large and small acinar pattern (130 cases) and 2) carcinomas with cribriform and/or solid pattern, partly mixed with other glandular types (178 cases). We applied a score of 10 points to divide the histopathologic regression into three gradings: pronounced, moderate, and poor or no regression. In adenocarcinomas a pronounced regression can be seen in 67.8% following three or more years of hormonal treatment, and in 64.7% following primary high-voltage therapy, mostly combined with hormonal treatment or orchiectomy. In adenocarcinomas with poor or no regression a percentage of 20.4 or 14.7, respectively, can be seen. In cribriform and solid carcinomas a significant difference is present between hormonal treatment and radiotherapy. Following hormonal treatment only 20.2%, but following radiotherapy 63.6% show a pronounced regression. Accordingly, 48.8% of these carcinomas show no or only poor regression under hormonal treatment after three or more years of follow-up. Following radiotherapy, there are only 21.3%. The conformity of locally palpable finding and histopathologic grading of regression reaches 70%. If no agreement can be achieved, cases with better palpable finding than histopathologically recognizable regression prevail.