Academic research is currently paying more attention to the time and speed aspects of the internationalization process. In line with this development, this study investigates the role of internationalization age and its impact on internationalization speed. It investigates as the main research problem the very impact that early versus late internationalization has on foreign sales’ subsequent growth and on the number of countries served once companies have decided to diversify geographically. The study’s emphasis is not restricted to the immediate post-entry speed of internationalization, but takes a longitudinal view as well. New data from a sample of Swiss SMEs provides evidence of a path dependency. The older an SME when it first expands abroad, the slower its subsequent internationalization speed. Internationalization age’s negative impact does not lessen in the short or mid-term, but even affects Swiss SMEs in the long term.