Based on literature in the field, the article examines the impact of the time factor on the international experience and level of internationalization of companies. The author seeks to identify the role of time in research on the internationalization of companies. The article is based on a critical analysis of research studies on the internationalization of companies, with a special focus on process models, a network approach to internationalization, and reports on accelerated internationalization. In particular, the author deals with research reports on the time and speed of internationalization. The article presents a number of proposals concerning the role of time in research on the internationalization of companies. These are linked with increased experience in business operations on foreign markets, the speed of internationalization, and the relationship between the time and level of internationalization. The author finds that, in order to better understand the process of internationalization, it is necessary to include the time factor in the theory of internationalization. Ratajczak-Mrozek argues that the relationship between time and an increase in a company’s experience abroad is complex and non-linear. The same is true of the relationship between the time and level of internationalization, the author says. She adds that the level of internationalization should be determined on the basis of comprehensive measurements taking into account resources involved at various levels of a company’s operations. Measurements of the speed of internationalization should take into account the speed of the whole process, and not be limited to the speed of a company’s entry into foreign markets the author argues. This is particularly important for the study of “born global” companies, Ratajczak-Mrozek notes.