||Slesma Sailendra Ras (SLS) an Ayurvedic preparation used as a traditional medicine in the treatment of cold, flu and fever in the rural population of Indian subcontinent. After 54 days chronic administration of the SLS preparation to the male rats at a dose of 400 mg/kg, the following toxicological changes were noted. In the male rats there were decrease in Total Protein, Albumin and Globulin content in the plasma. Statistically very highly significant decrease plasma Total Protein content was noted. There was a negligible increase Triglyceride level and VLDL content in the plasma whereas statistically very highly significant decrease in Total Cholesterol, HDL and LDL content. After chronic administration of SLS to the male rats’ decrease of plasma Bilirubin and Creatinine level were noted in comparison to their control group. On the contrary, a very highly significant decrease in urea & Urea/Creatinine level in plasma were noted. SLS caused decrease in plasma uric acid which was not statistically significant.