In 1960, there were 26 eunuchs from the palace of the Qing Dynasty still living in Beijing. The authors took that unique opportunity of carrying out a general physical examination, including palpation of the prostate, for every one of them. Their average age then was 72 years (59-83 years). They became eunuchs at the age of 10-26 years. The prostate was impalpable in 26 (81%) and 1-2 cm in width rectally in five, with a flat surface. At the time of the examination they had been eunuchs on the average for 54 years (41-65 years). This is probably the largest series of human beings followed for such a long period of time to confirm that testicular hormone is essential for the development and preservation of the prostate. The type of operation, the traditional way of carrying out the operation and the usual complications are presented.