BackgroundPurchasing drugs with or without prescription from retail drug shops is common practice in Bangladesh. However, what actually takes place between the drug seller and customer during the transaction is under-researched. This study explores the drug purchasing practices which underlie the socio-cultural and economic aspects of a Bangladeshi city.MethodsAdopting ethnographic methods, we conducted thirty in-depth interviews (IDIs) with customers, patients, and sales assistants, and ten key informant interviews (KIIs) with drug sellers, experienced sales assistants and pharmaceutical company representatives. Thirty hours were spent observing drug sellers’ and buyers’ conversations and interactions for medicine. A total of 40 heterogeneous participants were purposively selected from three drug stores. Transcribed data were coded, and analyzed thematically.ResultsWe found through thematic analysis that some individuals visited the drug store with fixed ideas about the name, brand, and dose of the drugs they wanted. Among the 30 IDIs participants, most individuals come without any preconceived ideas, describe their symptoms, and negotiate purchases with the expectation of quick remedies. Cultural practices of buying medicines in full or partial course of doses, with or without prescription, trust in sellers, and positive previous experiences of medications shape the drug purchasing behavior, regardless of any preconceived ideas concerning brand name, and dose. Few customers (n = 7) sought drugs by trade name, but most drug sellers often offered a generic substitute because selling non-brand drugs is more profitable. Notably, many of the clients (n = 13) bought drugs through installment payments and with loans.ConclusionCommunity people choose and purchase the most necessary medicines in a self-medicated way from shortly trained drug sellers that can harm individuals’ health and reduce the effectiveness of medication. In addition, the results of buying medicine through installments and loans suggest further research on the financial burden of consumers’ purchasing behavior. Policymakers, regulators, and healthcare professionals might implicate the study findings to deliver practical information on the rational use of medicines to sellers and customers.