Aqueous extract of the seed of Myristica fragrans (nutmeg) was evaluated for its phytochemical constituents, antinutrients and antioxidant properties. Toxicological investigation was also carried out using six groups of Wistar albino rats. The treatment groups were administered varying doses (100-500mg/kg body weight) of the extract for a period of 28 days. The animals were sacrificed and their livers, kidneys, hearts, spleen and testes harvested for histopathological studies. The results showed thatalkaloids, saponins, anthraquinones, cardiac glycosides, flavonoids and phlobatanins were present while tannins were absent in the aqueous extract. The phytate content was 564.11 mg/100 g while theantioxidant indices of 100 mg/100 g, 44% and 0.6 were obtained for the ascorbic acid value, free radical scavenging activity and reducing power, respectively. The results of the histopathological studiesshowed pathological features of various degrees in the organs with severity corresponding to the concentration of extract. There was lymphoid depletion of the follicles in the spleen, degeneration ofthe germinal epithelial cells in the testes, bile duct proliferation and congestion of blood vessels in the liver, degeneration, necrosis with desquamation of tubular epithelial cells and congestion of renal bloodvessels in the kidney and degeneration of myocardial fibres and myocardial necrosis in the heart in the treatment groups compared with the control. The present results suggest that nutmeg popularlyconsumed as food and for various medicinal purposes may contain some active principles with antioxidant properties. However, prolonged use at high doses (400-500 mg/kg) could be very toxic to the studied organ