Nymphaea nouchali (Burm. f) belongs to the family Nymphaeceae, which is a family of flowering plants. It is the national flower of Bangladesh and commonly known as "Shapla" in Bengali. N. nouchali is a large perennial aquatic herb with short round rhizomes. These flowers were recommended for traditional healers for treatments of renal diseases, piles and as cardio tonic and also had wide range of applications in ayruveda medicine. The present investigation was carried out to evaluate the safety of pet ether extract of Nymphaea nouchali (PNN) whole plant by determining its potential toxicity after acute and chronic administration in rats. Study on acute toxicity of extract found to be safe at the doses 2000mg/kg body weight orally as per OECD guidelines No.423. General behavior adverse effects and mortality were determined for up to 14 days. In the chronic toxicity study, the PNN was administered orally at doses of 100, 200 and 400 mg/kg once in a week for 6 weeks to rats. Biochemical and hematological parameters were determined after 6 weeks. In the acute study in rats, there was no toxicity/ death was observed at the dose of 2000mg/kg b.w. The onset of toxicity and signs of toxicity also not there. In the chronic toxicity study, no significant treatment-related changes in the levels of haematological, hepatic and renal parameters such as SGOT, SGPT, cholesterol, creatinine, urea, uric acid, protein and glucose, and serum ALP activities were observed at the termination of the study. It suggests that the pet ether extract of Nymphaea nouchali does not appear to have significant toxicity. In view of the dose of Nymphaea nouchali consumed in traditional medicine, there is a wide margin of safety for the therapeutic use of the pet ether extract of Nymphaea nouchali whole plant.