Acacia catechu (A. catechu) or Khair (Hindi) is used in several herbal preparations in the Ayurvedic system of medicine in India. Traditionally, this drug is beneficial against several gastrointestinal and stomach related ailments, and leprosy. The present investigation was carried out to evaluate the sub-acute oral toxicity of the ethanolic extract of A. catechu seeds in Wistar albino rats. Results obtained from the quantitative chemical analysis of A. catechu seed extract were compared with commercially available standards. A. catechu seed extract was administered orally at the doses of 250, 500 and 1000 mg/kg b.w. daily for 28 days. General behavior, bodyweight and mortality were examined during the entire study period. At the end of 28 days, hematological and biochemical parameters along with the relative organ weights were determined. It was observed that the extract did not induce death or any significant changes in the body weight, relative weight of vital organs and in hematological parameters for up to a dose of 1000 mg/kg. The oral administration of the plant extract did not produce any significant changes in the levels of glucose. In addition, there were no significant changes in the activity of both hepatotoxic and nephrotoxic marker enzymes in the serum. Oral administration of A. catechu also did not produce any significant changes in the levels of oxidative markers. Furthermore, the findings from the biochemical studies were, well corroborated with the histological findings.