Medicinal plants have various uses, one of which is in the treatment of infertility. Different parts of Palm, Phoenix Dactylifera of the Palmaceae family, are used as medicine. The objective of this study was to evaluate the influence of hydro alcoholic extract of Palm meristem. On the levels of gonadotropin (LH and FSH) and sex steroids (testosterone and dihydrotestosterone) in adult male rats with hypothyroidism. In this experimental study, 48 adult male wistar rats, each weighing approximately 190 to 200 grams and up to 3 months of age, were used. Animals were randomly divided into 6 groups of 8: The control received standard food and water, the sham got two ml distilled water, the experimental group 1 was orally treated with 25 mg/kg methimazolefor 10 days, the experimental group 2 orally received 200mg/kg Palm meristem extract for 21 days, and experimental groups 3 and 4 were first treated with 25mg/kg methimazolefor 10 days and then with 100 and 200 mG/kg extract for 21 days respectively. At the end of the experiment, blood samples were taken and the serum levels of LH, FSH, testosterone and dihydrotestosterone were measured by Elisa tests. The results were analyzed using SPSS software and ANOVA statistical test, and the significant statistical difference between control and experimental groups was considered 0.05 P=0.05. Results showed that mean serum concentrations of LH, testosterone and dihydrotestosterone hormones declined significantly in the experimental Group 1 compared with control and sham groups. Also, serum levels of LH , testosterone and dihydrotestosterone increased significantly in the experimental groups 3 and 4 compared with experimental group 1, however, only testosterone rose in the experimental group 2 in respect to sham and control groups. Comparison of mean serum concentrations of FSH showed no significant difference among various groups. Based on the results of this research and other studies, presence of antioxidant compounds and micronutrients in the Palm meristem extract are able to elevate the decreased levels of testosterone and luteinizing hormones, and improve the reproductive performance of testis through enhancing activities of thyroid hormones.