Introduction: The aim of this study is to investigate the relationship of melatonin supplementation with serum element metabolism in pinealectomized rats. Methods: The research was conducted on 32 adult male Spraque-Dawley rats. The study protocol was approved by the local animal ethics committee. Animals were divided into four equal groups. Control (Group 1), Melatonin (Group 2), Pinealectomy “Px” (Group 3), Pinealectomy+melatonin (Group 4). Animals in groups 2 and 4 were given intraperitoneal (ip) melatonin support (4 weeks/day; 3 mg/kg melatonin). Animals in groups 3 and 4 underwent pinealectomy under general anesthesia. At the end of the applications, serum element levels were determined by atomic emission (µg/dl) in the blood samples taken from the sacrificed animals. Results: While pinealectomy increased chromium and manganese levels in Group 3 (p<0.001), it caused significant suppression of magnesium, calcium and zinc levels (p<0.001). Melatonin supplementation in pinealectomized animals (Group 4) treated the impairments in the mentioned parameters. Conclusion: The results of the current study show that the melatonin hormone secreted from the pineal gland has a regulatory effect on serum element metabolism. This study is the first to examine the relationship between the pineal gland and element metabolism as a whole.