Innovative start-ups, including spin-offs from universities and companies, play a vital role in the development and growth of emerging, high-technology industries. Research attention has traditionally focused on the links between demographic, educational, psychological and financial influences on start-up activity and growth. The extent to which the characteristics of technology inherited from the parent, helps explain start-up performance, has been neglected. We analyse the scope and newness of the endowed technology as a predictor of growth for corporate and university spin-offs. Using a novel, hand-collected dataset, 48 corporate and 73 university spin-offs were identified, comprising the whole population of such spin-offs in Flanders over the period 1991-2002.