Vancomycin is a bacterial antibiotic used against resistant strains of streptococcus and staphylococcus, and one of the higher antibiotics to be used in treatment for the infections occurred in heart valve disease and in severe sepsis patients above 60 years .The main of the study is to determine the major clinical side effects of the vancomycin. It was a open label prospective and retrospective study. Among the 170 vancomycin injection received patients in the hospital with same brand, dose and frequency (1gm IV slow infusion) seventeen patients was observed with rashes over the neck and upper lymph.It is known as Red Man Syndrome or Dress Syndrome. In this study one patient associated with anaemia the dosing interval changed to prevent severe anaemia and another patient the drug was stopped because of severe reaction. The test dosing (10 microgram/ml) concept can be introduced before the administration of routine dose to minimize the clinical side effects. The treatment with antibiotic (linezolid or tigecycline) can be used as alternative.