Family physicians play a vital role in providing comprehensive, coordinated, continuous and patient-centred care to individuals and their families. One of the critical functions of family medicine in the healthcare system is gatekeeping, which ensures the efficient use of scarce healthcare resources by reducing unnecessary referrals to secondary and tertiary care. In this chapter, we first explore the uniqueness of family physicians in performing the function of gatekeeping. We will then discuss the benefits of gatekeeping, including reduced healthcare utilisation, healthcare costs and better quality of care. However, there are also potential challenges in gatekeeping, such as inadvertent barriers to specialist care, inadequate training and staffing in primary care, and the lack of clear referral guidelines and pathways. To overcome these challenges, we will discuss various strategies such as primary healthcare models, evidence-based consultation approach, enhancing communication and collaboration between primary and secondary care providers, injecting resources into the development of family medicine, the appropriate use of technology and the cost-effectiveness of primary care. Towards the end of this chapter, we will share the experience of using primary care point-of-care ultrasound to enhance the gatekeeping role of family physicians in Hong Kong.