The concept of transgenerational entrepreneurship postulates that the success of family firms across generations relies on three main dimensions—firm entrepreneurial orientation, familiness, and cultural contexts—which affect their financial, market, and social performance. The aim of this article is to empirically test the concept of transgenerational entrepreneurship using a large sample of family firms from 21 countries. Our results support and validate the main dimensions that form the concept and their structural relationships as well as highlight differences and similarities across cultural contexts.