Tamanu is an open-source electronic medical record system designed for health workers in the Indo-Pacific region, available for both desktop and mobile platforms. It facilitates the tracking of individual patients and offers clinical support for managing their conditions. The system is suitable for use in hospitals, clinics, and field environments and is optimized for offline functionality with seamless syncing capabilities. The fully integrated mobile and desktop versions do not require third-party integrations for essential features. Tamanu focuses on various health areas, including health promotion, communicable and non-communicable diseases, maternal and child health, vaccination/immunization, mental health, emergencies, sexual and reproductive health, chronic conditions, disabilities, oral health, and cancer.