Asian elephants (Elephas maximus) are considered an endangered species, and their reproduction in captivity is important for their conservation. In this study, we analyzed the impact of social pressure on stress status and the estrous cycle of captive female Asian elephants with the aim of determining the reason for their prolonged anestrous status. The levels of estradiol and progesterone indicate the estrous phase, and those of cortisol show stress status; therefore, we measured estradiol and cortisol in urine and feces, and progesterone in the urine of female elephants by radioimmunoassay. Social pressure was determined by the degree of aggressive and nonaggressive behavior. The results indicate the following: (1) females in a dominant position were more frequently engaged in aggressive behavior compared with those in a subordinate position; (2) cortisol levels in dominant females were significantly higher than those in subordinate females; (3) the levels of estradiol and progesterone in dominant individuals showed cyclic fluctuations, but those in subordinate individuals did not. These data suggest that among captive Asian elephants, social pressure may be the cause of low sex hormone levels and prolonged anestrus in subordinate females, which are therefore not engaged in reproductive behavior for a long time.