We study how three types of firm experience, ranging from the specific to the general, influence the perceived importance of institutional knowledge in the ongoing business of internationalising firms based on a sample of 101 small-to-medium-sized firms. The three types of firm experiences are international, country and ongoing business. The results show that firm experience within the ongoing business, and the experience from multiple past business deals in various countries, develop institutional knowledge, whereas experience from multiple past business deals in a specific country does not. The theoretical contribution of this paper is that it establishes a link between different kinds of experience and managerial cognition in terms of institutional knowledge. In addition, it emphasises that firms develop institutional knowledge from multiple diverse country experiences, and experience in the specific ongoing business rather than experiences at the level of the country.