Shaikh, et al.: Errors in Prescriptions Containing Non-steroidal Antiinflammatory Drugs Prescribing errors are one of the leading causes of diminished therapeutic outcomes even resulting in treatment failures. The Present study is a comparative evaluation of prescribing errors in non-steroidal antiinflammatory drugs containing prescriptions in four different health care facilities of District Khairpur, Sindh, Pakistan, since these drugs are among the widely-misused drugs. A total of 479 prescriptions, which were written in the primary health care facilities, public hospitals, university hospital and private hospitals were collected, compared and analysed for common omission and commission prescribing errors as per prescription writing guidelines/parameters established by the World Health Organization, The drug information book and the British National Formulary. Only 21 (4.4%) prescriptions consisting of 9 prescriptions of the university hospital and 12 prescriptions of the private hospitals were found error free and the rest 458 (95.6%) prescriptions from different health care facilities contained different types of omission and commission errors. In omission errors, patient diagnosis, registration number of the prescriber and duration of therapy was missing in 84, 88.9 and 82.8% prescriptions, respectively. Among commission errors, 85.2% of prescriptions were ambiguously written. A significant percentage of these errors were found in routine practice. As compared to all health care facilities, it was alarmingly found that, more number of prescribing errors were found in prescriptions of primary healthcare facilities followed by public hospitals followed by the university hospital and least number of prescribing errors were found in prescriptions of private hospitals. Computerized physician order entry and continuous educational training programs for prescribers to be executed in order to decrease these vital prescribing errors, besides that evaluation of prescriptions by pharmacists for prescribing errors can diminish the magnitude of these grave and life threatening errors.