The present study was planned in order to investigate the effects of various oral doses of water extract of Syzygium aromaticum buds, emphases of its effect were placed on changes of the growth, serological, hematological and pathological characteristics of Wistar rats. Water extract of Syzygium aromaticum was fed to Wistar rats at 50, 200, 400 and 800 mg/kg/day for two weeks. Impairment of growth and hepatonephrotoxicity were observed in the rats of all groups. These changes were correlated with alterations in serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) activities and total protein, cholesterol and urea concentration and hematology.