The aim of this study was to examine the presence of ${eta}$-endorphin in female reproductive organs. A total of 104 fresh tissue samples were obtained from normal ovary, tube, endometrium, placenta, amniotic membrane and umbilical cord, and immunostained by the method using biotin-streptoavidin amplified system. The results were as follows: 1. In reproductive age, corpus luteum only showed ${eta}$-endorphin immunostained cells but no cells in ovaries during proliferative phase of menstrual cycle were stained. 2. Secretory endometrium revealed positive reactions in the cytoplasm of glandular epithelial cells and around the vessels, while proliferative endometrium negative reactions. 3. All the tissues of menopausal women were negative to ${eta}$-endorphin antibody. 4. In the pregnant women, there are no ${eta}$-endorphin containing cells in the placenta, amniotic membrane and umbilical cord regardless of gestational age.