Purpose: The aim of this paper is to outline an innovative multilevel conceptual model capable of explaining “karoshi” (death from overwork) and its relationship to molecular-, micro-, meso- and macro-competitive productivity (CP). Design/methodology/approach: A theoretical model, grounded in the evolutionary biological, psychological, organizational and sociological literatures, is provided. Findings: Karoshi is a function of molecular (genetic), micro (individual), meso (organizational) and macro (cultural) evolutionary forces. It is also demonstrated to be a function of time, geography, agri-climate and cultural and ethnic homogeneity. Research limitations/implications: The analysis is purely theoretical and its theoretically informed hypotheses are not tested empirically. As such, further data-driven research is indicated. Additional analyses are also needed to further unpack the recursive nature of the relationship between karoshi and CP and the subtle differences between genetic evolution and cultural and organizational evolution. Practical implications: Karoshi-related deaths are a public health epidemic and increasingly a major obstacle to sustainable CP. As such, organizations can leverage these analyses to help them implement interventions aimed at reducing incidents of work-related deaths, not only in Japan, but across the world. Originality/value: This multilevel conceptual framework makes a unique contribution to the cross-cultural and strategic management literatures. More specifically, it constitutes a new and innovative contribution to one’s current understanding of CP by uniquely integrating biology, psychology, organization studies and cultural studies into one overarching model.