We investigate the extent to which a grocery retailer merger has different effects on the prices of national and store brands. Using retail scanner data, we retrospectively analyze a food retail acquisition in a large U.S. city. We focus on fluid milk and ready-to-eat (RTE) cereal categories, which represent a relatively homogenous and a relatively differentiated product category, respectively. We use a difference-in-difference estimation framework to obtain the causal effect of the acquisition on prices for the acquiring retailer. The primary finding is that the acquisition has heterogeneous price effects in the relatively differentiated RTE cereal category. The implications of results for consumers, food retailing, and merger analysis are discussed [EconLit citations: L11, L13, L22, L81].