The aim of this paper is to examine the causes of food waste and potential prevention strategies from a grocery retail store owner’s perspective. We therefore conducted a case study in a German region through semi-structured expert interviews with grocery retail store owners. From the collected responses, we applied a qualitative content analysis. The results indicated that store owners try to avoid food waste as this incurs a financial loss for them that directly affects them personally, as opposed to store managers of supermarket chains who receive a fixed salary. The main causes of food waste in the grocery retail stores in the region surveyed are expiration dates, spoilage, consumer purchasing behavior, and over-ordering of food products. The most appropriate food waste prevention strategies developed by store owners are those based on store owners’ experience and their own management style, such as the optimization of sales and management strategies, including precise planning, accurate ordering, and timely price reductions on soon-to-be-expiring food products. The redistribution of food surpluses as donations to food banks, employees, and as animal feed further helps to reduce the amount of food waste, but not the financial loss. This study enhances the literature by revealing that grocery retail store owners have the ability and are willing to successfully implement and enforce food prevention strategies in their stores.