Product innovation is the basic strategy by which organizations can survive in the current marketplace for a longer period. Therefore, the present study objective was to examine the impact of reward management, performance appraisal and career management on knowledge management effectiveness and product innovation. Additionally, knowledge management’s mediating role and the moderating role of technological capability are also examined in the present study. Data was collected from the employees working in the fiberglass manufacturing firms in Bahrain. The collected data was analyzed using PLS-SEM. The study findings revealed that knowledge management effectiveness within the firm is significantly impacted by HR strategies like performance appraisal, reward system, and employee career management. Moreover, knowledge management effectiveness also significantly impacts product innovation. In the end, the study also confirmed the moderating role of the technological capability of the organization on the path of knowledge management and product innovation. The present study fills the gap of limited studies, using HR capabilities to improve Bahrain’s fiberglass manufacturing firms’ product innovation. Furthermore, the findings of the present study are helpful for policymakers of manufacturing sectors to integrate HR initiatives into their product innovation strategies.