Pharmacy retail markets in low and middle-income countries (LMIC) have traditionally been dominated by independently owned pharmacies, but economic growth has spurred the entry of pharmacy chains into these markets. Chains could be argued to have the potential to both improve quality and reduce price in comparison to independent pharmacies, however this has been little studied in LMICs. Using mixed methods, including a standardised patient survey, exit interviews with patients, and key informant interviews, research was undertaken to understand the effect of chain pharmacies, in India, on key public health concerns. The management of childhood diarrhoea and suspected tuberculosis was similarly substandard in chains and independents for most areas of assessment. However, chains sold significantly fewer harmful and prescription-only medicines for the diarrhoea patient. No significant price difference was found between chains and independents for the management of the TB case but the diarrhoea consultation was significantly cheaper at chains. Chains offered discounts on medicines, made possible by bulk purchasing and efficiencies in the supply chain. Customers patronising chain pharmacies were both more educated and relatively wealthier than those using independent pharmacies. In-depth interviews explored a set of hypotheses regarding how being organised in a chain may affect key behaviours relating to quality failures. In practice, few differences were identified: chains did not all have qualified pharmacists; the chain structure was not used to enforce regulation; and chain sales staff faced quite high-powered financial incentives. Chains did exert strong influence over customer service and sales, but the potential to exploit this control to improve quality was not realised. Given that the chains are not currently serving poorer groups, and the impact on quality of care was limited, any attempt to leverage this organisational model for public health improvement would require implementation of appropriate regulatory constraints and incentives.