Objective To investigate the effect of Korean red ginseng total saponins (GTS) on ovarian morphology and nerve growth factor (NGF) expression in the ovaries, pituitary, and hippocampus. Design Polycystic ovary (PCO) rat model induced by estradiol valerate (EV). Setting University research laboratory. Patient(s) Thirty sexually mature female Sprague-Dawley rats weighing 190'210 g. Intervention(s) Female Sprague-Dawley rats (190'210 g) were separated into three groups: EV control (n = 10), EV plus GTS (n = 10), and oil control (n = 10). Main Outcome Measure(s) Ovarian morphology and NGF protein expression. Result(s) Polycystic ovary was fully developed in rats with a single intramuscular injection of EV. Increased expression of NGF was noted in the ovaries and the brain of rats with PCO. GTS administration attenuated NGF expression in the ovaries but not in the brain. Conclusion(s) Our findings suggest a role for GTS in the regulation of NGF expression in female rats with PCO.