This paper investigates whether the presence of ambitious entrepreneurs is a more important determinant of national economic growth than entrepreneurial activity in general. We use data from the Global Entrepreneurship Monitor to test the extent to which high growth ambitions of entrepreneurs affect GDP growth for a sample of 36 countries. Our results suggest that ambitious entrepreneurship contributes more strongly to macro-economic growth than entrepreneurial activity in general. We find a particularly strong effect of highexpectation entrepreneurship for transition countries. These results are interpreted in light of the ongoing debate about public policies designed to stimulate high growth start-ups.