Introduction & Objective: Disulfiram is used for treatment of alcohol intoxication.Based on the results of different studies, excessive amounts of the drug can affect the body's endocrine function. This study investigated the effect of disulfiram on the activity of the pituitary - thyroid in adult male rats.

 Materials & Methods: In this study 50 adult male Wistar rats weighing approximately 200 to 220 g were used in the experimental, control and intact groups. Experimental groups received 50, 100 and 200 mg/kg oral doses of disulfiram for 10 days and control group received 1 ml saline for 10 days and intact groups did not receive any thing. At the end of the tenth day ,the rats were bled from the heart and T3, T4 and TSH hormones were measured by commercial kits Gama Counter and the results were analyzed using one-way (ANOVA) with SPSS version 18.

Results: Results show that there was no significant changes in T₄ plasma level, but T₃ and TSH level increased significantly when the control and intact groups were compared.

Conclusion: Disulfiram had no significant effect in T₄ plasma level but T₃ and TSH level increased significantly. It probably happened due to increasing serotonin and reducing somatostatine and also enhancing the activity of 5-Deiodinase enzymes following the entry of calcium ions into the cells.