Objectives: This study was to evaluate the effect of Palmijihwang-whan (PMJHW) aqueous extract in the regulation of hypothyroidism related reproductive organ damages in propylthiouracil (PTU)-induced rat model. Methods: PMJHW aqueous extract (yield=17.90%) were administered, once a day for 42 days from 2 weeks before start of PTU treatment as oral doses of 500, 250, and 125 mg/kg (body weight), and hypothyroidism was induced by daily subcutaneous treatment of PTU 10 mg/kg for 28 days. Results: PTU-induced hypothyroidism and related male reproductive organ damages-atrophic changes of testis, epididymis and prostate, were favorably and dose-dependently inhibited by treatment of PMJHW 500, 250, and 125 mg/kg. They also effectively regulated the PTU-induced abnormal antioxidant defense system changes in the testis. Although levothyroxine also favorably inhibited PTU-induced hypothyroidism, it deteriorated the hypothyroidism related male reproductive organ damages through testicular oxidative damages. The results suggest that oral administration of 125, 250, and 500 mg/kg of PMJHW has favorable effects on the hypothyroidism and related reproductive organ damages through augmentation of antioxidant defense system in the testis. Conclusions: This study suggest that PMJHW may be help to ameliorate the hypothyroidism and related organ damages in clinics.