Majoon-e-Nisyan (MJN) is a polyherbal semisolid compound formulation. Its description is present in various Unani literatures. It is used in Unani medicine for its therapeutic efficacy against amnesia. There is no report regarding its safety on long term administration. Therefore, toxicological evaluation of MJN is carried out in rats. Majoon-e-Nisyan was subjected to 90-days repeated oral dose toxicity studies as per OECD guide line 408. Wistar rats were treated at three dose levels i.e., 500, 1000 and 2000 mg/kg bw and one vehicle treated group. MJN and vehicle were orally administered daily for 90 days and animal were observed for clinical signs of toxicity, mortality, body weight and feed consumption. On completion of 90-days, blood samples were collected and analyzed for hematology and biochemistry. Necropsy was performed on all survived animals and vital organs were collected and subjected to histopathology. No post dose adverse effect was reported on survival of both male and female rats after oral administration of MJN for 90 days. No incidence of mortality was reported in MJN treated male and female rats at all tested dose levels. No abnormal clinical signs were observed in MNJ treated animals at 500, 1000 and 2000 mg/kg bw as compared to animals of control group. No significant changes were observed in biochemistry, hematology and histopathological examination. No incidence of mortality, adverse changes in clinical signs of toxicity or body weight gain of rats was noted. No changes in clinical chemistry, hematology, and histopathology were observed in MJN-treated or control group. Therefore, NOAEL for MJN may be considered more than 2000 mg/kg bw in rats. Subject Classification Numbers: Pharmacology, Toxicology.