This study identifies the most relevant causes of food waste according to the perceptions of key stakeholders in Cluj-Napoca, Romania. Community-Based System Dynamics (CBSD), a qualitative approach, was used to reveal the determinants of food waste. CBSD was intended to encourage the system thinking of participants in the field of food waste. Consequently, CBSD helped us map and visualize the role of each identified cause in the system and the nature of their interactions. For the present study, four categories of stakeholders were involved: consumers, public administration, food waste business, and the NGO sector involved in food waste reduction. The result of each modeling session was a loop diagram of the main food waste determinants. A common perception reflected within each stakeholder group was that food waste could be minimized through upstream actions. The participants highlighted pro-environmental knowledge, awareness, and values as the prerequisites for fighting food waste. It was found that the lack of education and awareness of food waste directly impacted food waste generation. In addition, the role of education was underlined by participants as a contributor to changing individual and household practices, such as overbuying. The lack of connection between consumers and the food production process, coupled with consumerist practices and the rejection of ‘ugly food’, contributed to the decrease in the overall value people attributed to food. Governmental intervention, through legislation, was indicated by the CBSD participants as being key to increasing societal awareness and shaping the behavior of food chain actors. We concluded that food waste is a ‘wicked problem’ and the interlocking of the economic, social, political, and environmental spheres and the multitude of stakeholders’ interests, values, and perceptions should be considered in designing sustainable solutions to combat food waste. Finally, this research testifies to the importance of engaging with diverse panels of stakeholders who, through the multitude of opinions and perspectives on the causes of food waste, can further create knowledge about the most appropriate ways to combat the food waste phenomenon.