The present study was carried out during 2011-2012 to investigate the safety of Qurse-nazla by conducting acute and sub-acute toxicity in Swiss albino mice & rats respectively. Acute toxicity was determined by administering aqueous extract of Qurse-nazla orally to two groups of mice of six each at a dose 1gm/kg and 2gm/kg body weight. The animals were observed for gross behaviour and mortality for 24 hours after drug administration. The formulation was well tolerated by the animals and no abnormality was observed in the general behaviour (salivation, lacrymation, lethargy, sleep and coma) of the animals and no overnight mortality was recorded. Similarly, sub-acute toxicity was determined in albino rats by orally administration of aqueous extract to three groups of seven animals each at a dose ranges from 1gm/kg and 3gm/ kg body weight for 28 days. The results of haematology and biochemistry profile done on 29th day were found to be normal and no changes were observed in organ to body wt ratio of liver, heart, kidney and spleen.