Private hospitals, clinics, and pharmacies, and the doctors, nurses, and other medical personnel who staff them provide a large portion of healthcare services in low- and middle-income countries (L&MICs). In some, the private sector delivers much more care than the government. Understanding the scale, capacity, quality, constraints and motivations of private providers and private facilities – whether for-profit, non-profit, formal or informal – is critical to assuring that health services and medicines support and expand the goals of access to quality health care for all. This chapter sets out what is known regarding private care provision, from world-class hospitals to unlicensed and untrained village drug-sellers and summarizes the experience and frameworks being applied around the world to measure, regulate, and assure the efficient and effective provision of private health care as part of mixed-health-systems in L&MICs. In many settings the challenges of private sector governance are complicated by limited data, minimal financial transfers, and weak regulatory systems. Despite this, advances have been made in L&MICs to defining and applying good governance strategies.