PurposeDespite the undoubted role of knowledge in the small family business (FB) in the restaurant and fast-food industry, there are some main challenges in the knowledge-sharing (KS) orientation for promoting their business. This study tries to recognise and explore the drivers influencing these enterprises' KS processes.Design/methodology/approachThe authors applied combined exploratory and confirmatory analysis in two studies. In the first study, by the Delphi method, the 22 experts consisting of managers, FB owners and academic professors explore and forecast significant items and drivers. The second study is a confirmatory factor analysis (CFA) for validating the first study's indicators using the survey collected amongst 218 restaurants and fast foods employees.FindingsThe findings indicate 23 indicators in three main drivers of individual, organisational and technological, are critical for KS in small FBs in the investigated industry.Originality/valueThis research supports the understanding of knowledge management and the FB and contributes to recognising the influential factors for KS amongst small and medium-sized family businesses in the food-related industry. Also, by identifying and ranking the most significant factors, this research will help entrepreneurs facilitate FB entrepreneurship. Finally, the results provide practical implications for current and future KM and FB decision-makers.