Purpose – The purpose of this paper is to explore modern food retail buyers’ behaviour in developing economies using the case of Tanzania. This paper provides an insight into the decision-making practice of modern food retail buyers’ behaviour in emerging modern food distribution systems, where the buying task involves balancing the retailer’s commercial interests with more stringent government regulations that shape food business in the region. Design/methodology/approach – A qualitative case study approach was used for the study. The researcher used semi-structured interviews with retailers for data collection and corroborated them with secondary data. Data were thematically analysed. Findings – The study shows that the criteria used by modern food retailers in the selection of local food suppliers are reliability, quality, trade credit and legal certification. The task is further complicated by the overlapping food certification requirements of various government agencies, which impose limitations on the buyers’ decision. Due to the exploratory nature of the study and its focus on the context of a particular geographical marketplace, the findings may not be generalizable to other countries. Originality/value – This is the first academic study of the criteria used by modern food retailers in the selection of local food suppliers in Tanzania.