The previous evaluation (Borlaug et al. 2009) of FORNY, a Norwegian policy scheme to promote commercialization of research results from academic institutions, described the program’s engagement with academic spin-off companies in rather pessimistic terms. Most of the firms were small, unprofitable and showed few signs of growth. Further, in comparison with various other European countries, the results from the Norwegian start-ups seemed modest. Against such a backdrop, this thesis investigates why the growth processes of academic spin-off companies can be fragile. Through a case study investigation of six Norwegian academic spin-offs and a main theoretical perspective of first-mover (dis)advantages, intra-firm growth (or lack thereof) of such firms is studied. The analysis centers primarily around three dimensions: technological leadership, financial constraints and the presence of risk. It concludes that growth in these firms can be greatly affected by factors largely outside the control of the companies and that dimensions of time and timing can be particularly troublesome for academic spin-offs. When large uncertainties are present, the value of flexibility increases. However, academic spin-offs commonly have an undiversified business model where flexibility is limited; they frequently put every effort into one technology, and when this is an uncertain asset, their growth paths will often inevitably be precarious.