Non-communicable diseases (NCDs) are no longer confined to urban and rich persons. They impose a great risk in the low-income nations due to epidemiological and demographic transition. Adherence to medication is key factor in improving the quality of life and preventing complications of NCDs. This study was carried out to study the prevalence of medication adherence and factors determining non-adherence in elderly population with chronic diseases. A community based cross sectional study was conducted with 400 elderly aged 60 years and above. Data was collected by using a pretested questionnaire, which included socio-demographic variables, co-morbidities and details of their medication. Therapeutic adherence was assessed by modified Morisky-Green test, level of cognitive impairment by Pfeiffer’s short portable mental status questionnaire and functional dependence in activities of daily living by Katz Index. Statistical analysis was done using chi-square test. In our study, out of 400 participants, male participants were 184 (48%) and female participants were 216 (52%). 58.5% of them were adherent to their respective treatment medication. Male gender, low level of education, lower socio-economic status and cognitive impairment were the factors associated with therapeutic non-adherence. Therapeutic non-adherence is highly prevalent among elderly persons and is multi-factorial in origin. Interventions to increase adherence among elderly might effective if they are provided with proper guidance and education on the indications of individual treatments, their adverse effects, importance of adherence to medications and various consequences of non-adherence to the therapy.