Knowledge is a strategically important resource, but research is needed to elucidate individual issues in knowledge sharing, particularly cross-contextual examinations. Thus, we developed a contextualized, extended model of knowledge sharing intentions based on the theory of planned behavior, and tested it using large samples of employees from the US, and from Ukraine, where anecdotal evidence suggests pandemic knowledge hoarding. Tests of the model in each country produced significant results for all of the path coefficients in the US, and for all but two paths in Ukraine. Comparative analysis for hypothesis testing indicated that, overall, individuals' dispositions and attitudes were more relevant for understanding knowledge sharing intentions in the individualistic context of the US, while collective, relational elements were stronger in Ukraine, but with notable exceptions, particularly the influence of societal knowledge control norms. The results provide important implications for theory concerning knowledge sharing across contexts, including institutional theory assumptions, and for efficaciously managing knowledge processes, including cross-national knowledge transfers.