The aim of the study is to determine the toxic effect of omega-3 on the neurobehavioral and motor activity in the open field in male rats after 2 and 24 hr of treatment with 2000, 4000, 6000 mg/kg. The toxic effect of the drug on serum glutathione (GSH), malondialdehyde (MDA), triglyceride (TG) and glucose levels in male rats was also studied. In the determination of median lethal dose of omega-3, the result showed wide range of dose 1000–10.000 mg/Kg of body weight given orally without any mortality among the treated animals. The study appeared acute toxic effect of omega-3 by 4000 and 6000 mg/Kg of body weight given orally when compared with the control group. These changes were noticed by a number of neurobehavioral tests after 2, 24 hr of treatment. In open field, there was a significant decrease in the number of cross of squares and time of standing up of the rats. There was also significant decrease in numbers of head entrance in holes in pocking test. A significant increase in the negative geotaxis and cleft avoidance test was noticed after only 24 hours. In swimming test there was a significant decrease in score of swimming, while there was no significant difference in tonic immobility test after 2, 24 hr. However, there was no significant effect on all neurobehavioral tests by the dose 2000 mg/Kg the only significant decrease was noticed in number of head entrance in holes after 2 and 24 hr. In the biochemical tests, omega-3 at doses 4000 and 6000 mg/Kg did not produce a significant changes for serum GSH, MDA, TG, and glucose, compared with the control group. In conclusion, omega-3 is a non-toxic drug. Omega-3 produced neurobehavioral changes in high doses, without any significant change in lipid peroxidation, and serum GSH, TG, and glucose.