The main goal of the article is to determine the mediating role of human resources management (HRM) outcomes in the relationships between managerial staff development (MSD) and company performance results in multinational companies (MNCs) and to establish whether there are any identifiable regularities in this scope in four types of contexts, that is, the pre‐pandemic and pandemic period in the headquarters (HQs) and foreign subsidiaries of MNCs. This article presents an innovative approach to analyzing the relationship between these variables. To capture the actual relationships, the efficiency index was introduced which makes a novelty in the studies on management of MNCs. Additionally, the empirical research was conducted in MNCs established in Central Europe, which is not a frequent subject of research. The research findings show that in the foreign subsidiaries of MNCs, during a pandemic, the results in HRM mediate the relationships between MSD and company's performance results in finance, innovativeness, and quality stronger than in the pre‐pandemic time. As for the HQs during the pandemic, this mediation effect was stronger when innovativeness was considered, stayed the same for quality, and decreased for finance.