Thirty healthy bulls of ages between 12-18 months were used in this study to evaluate three surgical techniques of castration from the clinical, endocrinological and histopathological points of view. Twenty bulls were conventionally castrated by Burdizzo's bloodless technique, 5 bulls by the standard-open technique and 5 bulls castrated by complete ablation of the scrotum and testes. Castration and ablation of the scrotal sacs have had many advantages over other techniques. On the other hand bloodless castration was found to be easy to apply and appeared suitable for large scale program in bulls. A reduction in the testicular volume was started 15 days postcastration as detrmined by calibration as well as the gross pathological examination. By the 7th day postcastration no detectable testosterone was measured regardless to the method of castration. After bloodless castration, gross examination of the testes revealed an increase in size during the first week, followed by progressive decrease until became equal in size to the spermatic cord at the 70th day postcastration. Decrease in the intensity of colour and increase in the firmness occured parallel to the decrease in size. Histologically, there was congestion , edema and hemorrhage of the testicular tissue in the first week. Thereafter, the seminiferous tubules showed necrosis and the testicular tissue was invaded by granulation tissue, with increasing severity up to the 70th day postcastration. Starting from the 35th day postcastration the accessory genital glands shwoed atrophy, loss of the secertory activity and fibrosis, with changes in shape and size, regardless to the method of castration. By 60 days postcastration a marked decrease in the mean weight of the seminal glands and bulbourethral glands was found.