Drawing on the conservation of resources (COR) theory, we examine the role of two types of family support—emotional and instrumental support—in work-family balance and subjective well-being of small and medium enterprise (SME) owners. Using a sample of French SME owners, our results show that work-family balance mediates the relationship between family support and subjective well-being of SME owners. Surprisingly, while emotional support has a positive association, instrumental support has a negative association with the subjective well-being of SME owners via work-family balance. We provide a theoretical explanation by integrating COR theory with the threat to self-esteem model