Aim To assess adherence to prescribed medications for chronic illnesses and to identify factors associated with it among rural older adults. Methods A cross‐sectional study was carried out from September to November 2011 in three subcenters in Lakkur PHC, Kolar District, India. All older adults were listed, and those suffering from chronic non‐communicable diseases were included in the study. A structured interview schedule comprising of 48 items was used to measure adherence, and to identify factors associated with adherence in the domains of socioeconomic status, therapy, health systems, patient behavior and physical factors. Results Of the 184 older adults included in the study, 63.6% were fully adherent to their medication. Non‐adherence to medication showed a statistically significant relationship with the absence of a medical store within their village, non‐availability of drugs at the nearest medical store, inability to understand the doctor's language, failure to explain the consequences of not taking medicines by the healthcare provider, self‐alteration of medicine dosage, fear that medicines will lead to the development of dependence to medicines and difficulty in swallowing. Those who led busy lives, those who had been prescribed three or more types of medicines prescribed per day, those who required special skills to take medicines (injections, inhalers), those who had made adjustments to their usual lifestyle to take medicines and those who had knowledge that medicines need to be taken lifelong were more likely to be adherent to their medications. Four factors, namely, the doctor explaining the consequences of not taking medicines, altering the dosage of the medicines by the patients themselves, the number of medicines prescribed per day and having the knowledge that medicines need to be taken lifelong, were critical determinants of adherence to medications. Geriatr Gerontol Int 2016; 16: 1339–1345.