In 2006, the Dutch health insurance system was radically reformed to strengthen competition among health insurers as purchasers of health services. This article considers whether purchaser competition has improved efficiency in health-care provision. Although supply and price regulation still dominates the allocation of health services, purchaser competition has already significantly affected the provision of hospital care, pharmaceuticals and primary care, as well as efforts to gather and disseminate information about quality of care. From this perspective, the glass is half full. However, based on the crude performance indicators available, the reforms have not yet demonstrated significant effects on the performance of the Dutch health system. From this perspective the glass is half empty. The article concludes that the effectiveness of purchaser competition depends crucially on the success of ongoing efforts to improve performance indicators, product classification and the risk equalisation scheme.