The current study aimed to investigate the effects of prenatal melatonin “MLT" administration against bisphenol A “BPA"- induced infertility and thyroid dysfunction in male rat offsprings (First generation “F1"). For that purpose, fifty adult albino rats (40 females and 10 males) were used and classified equally into five groups (8 females and 2 males in each group). First group (control group) in which, pregnant rats were injected with 0.3 ml of vehicle /day. The second group (low dose BPA) where rats received a daily dose of 25 µg / kg B.W. The third group (high dose BPA) where rats received a daily dose of 250 µg / kg B.W. Fourth group (low dose BPA + MLT) where rats received a daily dose of 25 µg BPA /kg B.W. plus 10 mg MLT / Kg B.W. The fifth group (high dose BPA + MLT) where the rats received a daily dose of 250 µg BPA / kg B.W. plus 10 mg /Kg B.W. All rats within each group received their specific treatment daily with subcutaneous injection starting from the fourth day of pregnancy till full term. Then, the male offsprings of each group were selected and reared until the 60th day after birth. Serum and tissue samples were collected for analyses and microscopical examination. Although prenatal administration of both BPA doses didn't affect the body weight gain and testicular weights of male offsprings, they reduced significantly the serum levels of testosterone and triodotyrosine when compared to the control group. Also, both BPA doses disturb significantly the oxidant/antioxidant ratio. Moreover, prenatal administration of both BPA doses affected negatively semen quality of the produced offsprings and induced marked histological alterations in their testes and prostate. Remarkably, all serological and histological alterations observed after BPA exposure were ameliorated significantly with MLT co-administration. Thus, prenatal MLT administration could be considered an optimal treatment to relieve many reproductive disorders, degenerative changes of testes and prostate and thyroid malfunction induced in male offsprings after gestational exposure of their dams to BPA.