Bilateral cryptorchidism occurs naturally and is characterized by azoospermia (Ott & Memon 1980, Theriogenology 13(2): 155-164). These rams usually have a normal behavior towards ewes. Azoospermic animals can serve as a safe tool to detect estrous females for various purposes without risking impregnation. Ten cryptorchid Sarda breed rams aged between 2 and 3 years old, with previously confirmed azoospermia, were tested according to pen libido test (Mattner, et al. 1971, Aust. J. Exp. Agric., 11(52): 473-477). Each male was introduced with 5 females, 3 in heat after hormonal synchronization and 2 controls (untreated). Sexual behavior of the male was recorded for 20 minutes including: approaches, flehmen, reaction time to mount, and reaction time to service. 90% of males were found to have actively approached females, reacted with a flehmen and were able to detect and complete a successful mount on the females in heat. Only 20% of males hesitated at first before attempting to mount the females. Only one of the males showing attachment to the caretaker was distracted and had no interest in the estrous females. Mean reaction time to mount was recorded at 1.36 minutes, while that to service was at 2.34 minutes. These results demonstrate that cryptorchid males could be considered as an effective tool to detect females in heat. They appear to be highly capable of distinguishing between females in heat and those that are not. It is however recommended to test such rams for their libido and ability to detect estrous females prior to their use in reproduction-related activities. Further studies on assessing their ability to induce a successful ram effect on a flock would be needed.