Aim: The aim of this study was to gain more insight into patients' reasons for discontinuing chronic medication. Methods: Electronic medication overviews recorded by a pharmacy were analysed with respect to patients' return behaviour during 3 months following their first prescription. Patients who did not return in time were interviewed by telephone to find out their reasons for either returning too late or not returning at all to the pharmacy to collect their repeat medication. Results: Of 232 first-time chronic medication prescriptions, 132 were not collected at all (46.1%) or too late (11%). These prescriptions involved 121 patients, 113 (93.4%) of whom participated in the telephone interview. Twenty patients returned too late to collect their repeat prescriptions, largely because they had forgotten to take their medication according to schedule (n = 13). Ninety-three patients did not return to the pharmacy at all because of side-effects (24.5%), inefficacy (16.4%), medication not intended for chronic use (15.3%) and absence of need for continued use (14.3%). Conclusions: About 50% of patients who have been prescribed chronic medication for the first time stop using their drugs within a matter of months. Perceived drug side-effects, drug ineffectiveness and personal considerations related to use and a lack of need of treatment were the main reasons for discontinuing chronic drug therapy. This kind of noncompliance may result in an increased health risk as well as constituting a waste of a large amount of money. Adequate patient counselling and shared decision-making between doctors and patients are needed to prevent the unnecessary cessation of chronic drug therapy.