This study examines the impact of organizational culture on the effectiveness of Project Portfolio Management (PPM) practices. Organizational culture influences employee behavior and their way of working by providing a conducive work environment. Thus, managers are able to delegate better while ensuring a balanced workload, collaborative team efforts, and prudent resource allocation to achieve desired project portfolio deliverables. By shaping practices and values, a supportive culture enables efficient task performance, effective delegation, teamwork, and resource allocation toward project goals. Conducted with 35 individuals in a healthcare organization’s data and digital unit in New Zealand, the study used convenience sampling and email surveys. Regression analysis was performed in IBM SPSS Statistics to test the research hypothesis. Findings suggest that supportive organizational culture significantly enhances PPM execution and informs policy-making for improved PPM practices. This study facilitates directors, strategists, and managers in taking steps to form a culture that ensures effective execution of PPM practices to achieve better results. Future research could explore this topic with larger samples and alternative methodologies to deepen insights into culture’s role in PPM effectiveness.