This study investigates the relationship between transformational work performance and organizational efficacy in selected Nigerian petroleum companies. It is anchored in transformational leadership theory and the high-performance work systems (HPWS) framework. Transformational leadership, pioneered by Burns and developed by Bass, emphasizes leaders' influence through idealized influence, inspirational motivation, intellectual stimulation, and individualized consideration. The HPWS framework highlights HR practices that enhance employee skills, motivation, and opportunity, ultimately driving organizational performance. While existing literature on transformational leadership mainly focuses on Western contexts, this study seeks to address the gaps by examining its applicability in Nigeria's petroleum sector. Methodological limitations, organizational-level focus, and contextual specificity are identified as gaps in prior research. The study aims to investigate these relationships in Nigeria, considering sociocultural variations and employing a mixed-methods approach. Through structured interviews and questionnaire surveys, data were collected from 280 employees. The data analysis included regression analysis, correlation analysis, and reliability testing. Results indicate a significant positive relationship between transformational leadership dimensions and organizational efficacy. The study contributes to understanding the dynamics of transformational leadership and HPWS in a developing economy context, particularly within Nigeria's petroleum industry. Future research should explore these relationships further, considering contextual factors and employing longitudinal designs.