||Medication errors are important problems in hospitalized and outpatients department. Medication errors are inevitable and are affected by numerous human factors. Nevertheless, the epidemiological data about medication errors in outpatients in India is still limited. Objectives: This study was purposed to know the occurrence of medication errors including prescribing error, pharmaceutical error and dispensing error and the occurrence of the most type happened in these errors in outpatient settings. The present study is a prospective and study subjects were selected from community based ambulatory pharmacies. The study was carried over one month during January 2012. 250 prescriptions were collected and 212 of them were selected for the further analysis. We observed the prescription of 202 outpatients (of 212, 10 were excluded). About 81% of prescriptions were carrying with variety of errors. Among 202 prescriptions, 95.54 % were with prescribing errors, 9.9 % were with pharmaceutical errors and 7.91% were with dispensing errors. The most type of prescribing error was incomplete prescription orders and it was the most common stage of errors (95.54%). The dosing errors were including over dose and under dose of drugs, while dispensing errors includes improper drug preparation and incomplete or no drug information. Medication errors are still common problem in outpatients in Chidambaram, India. Pharmacists needed to prevent and overcome the medication errors.