This panel illustrates alternative approaches to theorizing by drawing on Reijo Luostarinen’s – Professor of International Business at the Helsinki School of Economics and EIBA Fellow – experiences. His research is one of the neglected treasures of the International Business (IB) field. Compared to the Uppsala Model of internationalization, which was also developed at the same time in the 1970s, Luostarinen’s theory is as groundbreaking but more comprehensive and far less known within the IB community. This panel raises the question: What can we learn about theorizing from the original example set by Reijo Luostarinen? The panel introduces four alternative perspectives on the process of theorizing inspired by Reijo Luostarinen’s experiences, with each panelist representing one perspective: i) a pragmatic approach to theorizing (Joep Cornelissen); ii) a phenomenon and agent-based approach to theorizing (Khadija van Straaten); iii) a location-based approach to theorizing (Rebecca Piekkari); and iv) a meta-theoretical (systems) approach to theorizing (Catherine Welch). This design gives coherence to the panel.