Drawing on identity theories and entrepreneurial identity, we examine how multiple identities relate and change across generation in the pursuit of portfolio entrepreneurship in the family business context. Using an inductive, qualitative approach based on multiple case study design of 12 farming business families, we discover that next generation family members engage in new business creation to build a positive work identity, that is to experience multiple identities as compatible with one another. We develop a process model that contribute towards our understanding of how next generation family members organize their multiple identities, which results in identity change over generations. A positive relationship between multiple identities leads moreover to beneficial outcomes such as positive emotions and finding meaningfulness in work. Our findings have implications for the literature on entrepreneurial identity, portfolio entrepreneurship and family business.