A safety evaluation of marbofloxacin was carried out following repeated intramuscular (5 mg/kg of body weight for 5 days) administration alone and piperine pretreated (10 mg/kg, P.O. for 5 days) rats. The blood samples were collected into sterile K 3 EDTA and non-heparinized test tube on 0 day (before treatment) a nd 6 th day (after treatment) monitored by estimation of va rious haemato-biochemical parameters.The average values of hematological parameters, viz., HB, PCV, TLC, TEC, DLC, MCV, MCH and MCHC were estimated before and after drug administration. The average values of blood biochemical (ALT, AST, Total protein, Albumin, Globulin, LDH, Creatinine, BUN, Bilirubin and AKP) parameters were measured before and after drug administration. The values of HB, PCV, eosinophil and monocytes were found be significant (p<0.05) when compared to before treated values. No significant alterations in mean values of all serum biochemical parameters were observed after treatment compared to (0 day) before treatment. All the rats were found no clinical signs and others adverse reactions.It is concluded that marbofloxacin following repeated intramuscular alone and piperine pretreated rats did not show major significant alterations in the haemato-biochemical parameters. Marbofloxacin was found sa fe and well tolerated antibacterial agents to be used against bacterial infections.