Sertraline is an antidepressant drug. Sertraline was labeled with I-131 by using iodogen method. Labeling yield was 85-90% and specific activity was approximately 64.75 GBq/mmol. The purification of radioiodinated Sertraline was performed by Sep Pak C-18 plus and the radiochemical purity was determined to be over 99%. Biodistribution studies were carried out by male Albino Wistar rats. The percentage of injected radioactivity per gram of tissue was calculated, and these data versus time curves were generated for organs and brain regions. The results showed that I-131 labeled Sertraline may be a promising radiopharmaceutical for the investigation of serotonin 5-HT receptor functions of brain.