This project examined a unique sample of 600 independent young high-tech firms which were originally surveyed in the Anglo-German Foundation study of "The Rapid Internationalisation of High Tech Young Firms in Germany and the United Kingdom" (Bürgel, Fier, Licht and Murray, AGF 2001). These firms which were started in the period 1987-96 were surveyed by postal questionnaire in Autumn 1997. This research project ascertained by telephone survey conducted in 2003 the survival and growth rates of this cohort of firms in both countries. The study determined empirically what key, firm-based factors are associated with continuing longer term success as defined by both survival rates and exceptional growth rates in sales revenues and/or employment, i.e. how many start-ups continued to grow significantly beyond the numbers of the original founding team. Thus, the project addressed directly the critical issue of the ability of European knowledge-based firms to grow into world class businesses. It also dealt with questions related to resource-based perspectives of firm growth. Moreover, the project analyses the current stage of the firms´ internationalisation process. The results show that on the one hand some firms left international markets because of the current difficult market conditions, but on the other hand a comparable high number of firms entered into the international markets for the first time since the first survey was carried out. Firm-specific resources - R&D in particular - facilitate a long-term international engagement and prevent firms from exiting the foreign market. In this context, the continuing role of internationalisation on the performance of the respondent firms was examined. The first study revealed that internationalisation significantly increased the rate of sales growth (but not employment growth) during the early stages of a firm´s history. However, the recently conducted survey showed that both the productivity-enhancing effect of internationalisation and the (sales) growth-increasing effect are restricted to early stages high-tech firms development and do not appear when the firms are analysed during later stages of their life cycles. The causality runs in the reverse direction: Firms that exhibit superior performance are or will become exporters. An analysis of the firms´ surival rates revealed that more than three-quarters of German and UK firms have continued to survive from 1997 to 2003. Innovative firm more likely survive in a rapidly changing environment than non-innovative firms. Moreover, firms that experienced a strong shortage of skills in the areas general management and financial management exhibit a smaller probability of survival than firms without such deficiencies.