The present study was carried out to evaluate the acute and sub-acute toxicity of Algerian Peganum harmala L. seeds (Zygophyllaceae). For the acute toxicity assessment, oral administration of P. harmala crud extract to mice in single doses of 0-12 g/kg caused dose-dependent general behavior adverse effects and mortality with LD50 of 2,86 g/kg. In the sub-acute study, daily oral administration of the crude aqueous extract for 28 consecutive days did not result no mortality. However, our results showed a significant difference in organs weights between control and treated animals. In the biochemical analysis, significant changes occurred in Bilirubin, uric acid (UA) and alkaline phosphatase (ALP) in the treated animals when compared to the control ones. Hematological analysis showed differences in WBC count and Hemoglobin estimation. However, urinalysis was negative for all parameters except Glucose in the treated group. Pathologically, a few gross abnormalities and histological changes were observed in hepatic and nephritic tissues.
 Keywords: Peganum harmala L., Acute and Sub-Acute Toxicity, Hematological parameters, Biochemical parameters