The aim of this article is to make a contribution to the understanding of how knowledge can be accumulated in family business. Four family firms from Switzerland and Italy are part of this research. Existing literature combined with the case studies analysed lead to the development of a model that outlines factors responsible for knowledge accumulation viewed as an `enabler of longevity' in family business.The relationships depicted in the model can be read by researchers as hypotheses and suggestions for further research, and by managers as possible factors needed to accumulate knowledge in order to be successful across generations.