The toxic effects of diet containing 10% of C. senna L. fruits or 10% of N. oleander L. leaves or their 1:1 mixture (5% + 5%) on male Wistar rats treated for 6 weeks were investigated. Diarrhea was a prominent sign of C. senna L. toxicosis. In both phytotoxicities, there were decreases in body weight gains, inefficiency of feed utilization, dullness and enterohepatonephropathy. These findings accompanied by leukopenia and anemia were correlated with alterations of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activities and concentrations of total protein, albumin, urea and other serum constituents. In both phytotoxicities, the ability of the liver to excrete bilirubin remained unchanged. Feeding the mixture of C. senna L. fruits and N. oleander L. leaves caused more serious effects and death of rats. The implications of these findings are discussed.