The plasma levels of beta-endorphin were studied in 64 women with polycystic ovarian disease (PCOD), from whoin was selected a group of 23 women until normal weight and amenorrhea of < 36 days. On nay 21, beta-endorphin levels were:,mean 64.92 pg/ml; SD 37.32pg/ml; 95% CI 48.38-81.47pg/ml. It war also observed that their levels of opioid peptide were reduced, compared with women who Iran normal ovulatory cycles, both in I the follicular phase (mean 70.93pg/ml; SD 24.59pg/ml; 95% CI 76. 84-99. 77 pg/ml) ar ln luteal phase (mean 88.30 pg/ml; SD 31.80 pg/ml; 95% CI 76.84-99.77pg/ml). The results were statistically significant (p < 0.05) for levels iri PCOD patients compared with there of the luteal phase in women with normal ovulatory cycles. The decreased levels of beta-endorphin level were negatively related to luteinizing hormone (LH) levels, which might explain the rise of LH levels in women with PCOD who control their weight and at the time of amenorrhea, although it is riot clear if central opioid activity is reflected in the peripheral blood.