•We focus on an exporter’s foreign market entries, exits and re-entries.•Knowledge, networks and decision-making logic intertwine during internationalization.•Lack of knowledge results in effectual decisions and “experimenting” with markets.•Knowledge acquisition leads to more causal (plan-driven) decisions and stronger ties.•Experienced firms still exit and re-enter markets, and enter new ones “by chance”. We focus on the following question: how are knowledge, network relationships and decision-making logic interrelated throughout the internationalization process – foreign market entries, exits and re-entries? We contribute to the internationalization literature, network approach and effectuation theory that have not examined these interrelationships during internationalization – especially de- and re-internationalization – in detail yet. Thereby, we provide a more complete view of internationalization. Based on a single punctuated longitudinal case study, we show that lack of knowledge results in mostly effectual (opportunity-driven) decision-making: finding customers via weak ties, trade fairs and unsolicited export orders and experiencing numerous market exits and re-entries due to “experimenting”. Knowledge acquisition leads to more causal (systematic, plan-driven) decision-making and stronger ties, but serendipitous (“by chance”) entries can still occur, and exiting and re-entering foreign markets may continue. We suggest that managers should network and acquire knowledge actively, use both decision-making logics and accept uncertainty as normal during internationalization.