To explore and estimate the frequency of medication error, a study conducted in a Ruby General Hospital, Kolkata. The medication error can be divided into Prescribing errors, Dispatching Error, Drug Administration Errors, and Indenting Errors. The purpose of this study is to determine the prevalence and nature of medication errors; to explore the causes and to study corrective actions for such medication error. Identify and evaluate the failures of medication errors and its severity analysis in a Ruby General Hospital, Kolkata and suggest solutions on reducing medication errors. It is a prospective study of patients receiving medication during treatment. The techniques that were used to identify the medication errors the study was carried out in a Tertiary Care 320 bedded Teaching hospital at Kolkata. Data taken from Medication Error reporting form and Photocopy of medicine card of patients. Proper monitoring and capturing of medication error data has been initiated. Staff has been counselled and sensitized regarding safe medication practices and proper reporting of medication errors. Regular training on medication error has been conducted by Clinical Pharmacy Department, which improve the knowledge of monitoring, capturing, reporting and prevention of medication errors by the physicians, nurses, and clinical pharmacist.