This study was conducted to investigate the effect of progesterone on the oxygen consumption of washed goat spermatozoa. The results obtained were summarized as follows: 1. Progesterone significantly depressed the respilation of the spermatozoa. 2. Caffeine and Di-cAMP greatly increased the oxygen consumption of the spermatozoa. 3. Caffeine plus progesterone and Di-cAMP plus progesterone significantly depressed the oxygen uptake of the cells. 4. There is some indication of a relationship between progesterone and its interference with metabolic behavior of sperm.