The effect of water extract of Hyptis suaveolens (H. suaveolens) was evaluated for 6-month chronic toxicity in Wistar rats. Control group received distilled water orally 10 ml/kg/day. The extract was orally given to five treatment groups at the doses of 5, 50, 250, 500 and 500 mg/kg/day for 6 months. The last group was served as the recovery group. Changes in the body weights, actual and relative organ weights were not significantly demonstrated in all groups throughout the study. The results of hematological, biochemical parameters and histopathological lesions showed that the extract did not produce any significant doserelated changes. Therefore, it may be concluded that the extract of H. suaveolens at the given doses did not produce any significant toxic effect in rats during 6-month period of the treatment.