Improving early diagnosis capacity is an important strategy to cancer control in all settings, strengthening health systems and providing universal health coverage. It is founded on core principles in delivering clinical services that include community empowerment and engagement, improving health literacy, access to primary care, diagnostic capacity including pathology, strong referral mechanisms, coordination and accessing timely treatment. Effective cancer care requires that these services are accessible, well coordinated and provided without delay. This guide is intended to support programme managers in cancer control by clarifying the concept of early diagnosis and helping users to operationalize early diagnosis programmes. Implementing the elements of this guide will depend on the local context. There is no single approach that fits all situations thus necessary adaptations are needed. Action is needed urgently to reduce premature mortality from noncommunicable diseases (NCDs), including cancer, and to achieve targets in Global Action Plan for the Prevention and Control of NCDs 2013–2020 and 2015 United Nations Sustainable Development Goals. In all countries, the desire to detect cancer early means that governments must address barriers to timely cancer diagnosis and to high-quality cancer care.