Osteoarthritis (OA) is defined as a disorder that involves the movement of limbs characterized by cellular stress and a deterioration of the outer matrix that trigger malignant remodelling responses that include inflammatory mechanisms of natural immunity. Non-steroidal anti-inflammatory (NSAID) drugs are the first choice of treatment, since they reduce pain, improve functional ability. So, by comparing the effectiveness and safety of NSAID used in the treatment of OA can enhance the quality of life of patients. The goal of the study was to compare the effectiveness and safety of Aceclofenac and Etoricoxib in OA patients as well as to assess the quality of life (QOL) and medication adherence among subjects. It is an observational study conducted in the selected Orthopaedics clinics in T. Dasarahalli, Bengaluru District for a period of 6 months, based on various inclusion and exclusion criteria. Standardized questionnaire used in the study were Western Ontario and McMaster Universities Arthritis Index, Medical Outcomes Study 36-Item Short-Form Health Survey and Morisky Medication-Taking Adherence Scale. The collected data were entered in Microsoft Excel and appropriate descriptive and inferential statistical analysis was performed. On comparing Aceclofenac and Etoricoxib in terms of WOMAC score Etoricoxib (28.42) was found to be more effective than Aceclofenac (31.61) while comparing Etoricoxib 60 mg and 90mg, 90 mg (26.22) was found to be more effective. Regarding the safety of these drugs, Etoricoxib was found to be safer than Aceclofenac in terms of side effects. On associating the QOL scores in both the groups, it was found that the subjects belonging to the Aceclofenac group had the highest overall mean score 57.68. Investigation of medication adherence in the study population revealed that out of 68 subject’s majority of them had shown low adherence (n=38). Because of its enhanced safety profile, Etoricoxib is a better option than Aceclofenac for treating .....