The present study was aimed to assess, understand and study the prevalence, risk factors and pharmacoeconomic details of Osteoarthritis (OA). We conducted a prospective, observational, cross sectional study on 68 OA patients for a period of 6 months in a tertiary care referral hospital, Kerala. A data collection form was designed to collect information necessary for the study. We arranged the study into 3 phases as the preparatory, data collection and analytical phase. The prevalence of OA and prevalence of each risk factor to causing OA was separately analyzed. The cost of illness in OA patients was also evaluated. Among 68 patients selected for the study, 32 patients were from the age group 56-65 followed by the age group 66-75 of 18 patients. Out of 68 patients, 47 patients were females and 21 patients were males. Our study found that 40 patients were overweight, 19 were obese and only 9 were normal weight. The assessment of prevalence of risk factors showed that among the various risk factors, age (36%) was found to be the most statistically significant prevalent risk factor followed by female gender (69%) and trauma (16%). The average monthly cost of treatment of osteoarthritis was calculated from the collected data and it was found that direct medical cost was more than the direct non medical cost. Our study concluded that a high prevalence rate of knee osteoarthritis among elderly. Also females were predominantly affected than men and prevalence of risk factors was also higher in this gender. Our study suggested that as the number of people with OA increases with age, preventive measures can be taken in the earlier age groups by lifestyle changes and by careful watch on body weight and daily activities. So that Osteoarthritis can be prevented.