Development Media International (DMI) creates evidence-based behaviour change campaigns to improve health and save lives. We deliver at scale to maximise impact and cost-effectiveness. We are the first organisation to scientifically demonstrate that mass media can increase life-saving behaviours. In 2018 DMI published the results of its 5-year, £7m randomised controlled trial (RCT) in West Africa which showed that 56% more children were taken for treatment for malaria, 73% more for diarrhoea and 39% more for pneumonia following exposure to our campaign. Modelling indicates that over 3000 lives were saved during the campaign and that our approach is one of the most cost-effective ways of saving children's lives. We have subsequently undertaken a second RCT which showed that the modern contraceptive prevalence rate was 20% higher in areas exposed to DMI's messaging compared to areas that were not.DMI has two priorities: first, to continue to generate ground-breaking research, second, to take our proven strategies to scale, saving as many lives as possible and improving health. We work across a range of health issues, including child survival, reproductive health, nutrition, hygiene, and early childhood development. DMI works in close partnership with leading experts in health, including WHO, UNICEF and LSHTM and has been funded by some of the world's most prestigious organisations including the Wellcome Trust, DFID, Comic Relief, the Global Innovation Fund, Unorthodox Philanthropy and the Mulago Foundation.DMI has a permanent presence in Burkina Faso, Madagascar, Mozambique, and Tanzania and also currently works in Côte d'Ivoire, Mauritania, Malawi, Uganda, and Zambia. DMI's headquarters overlooks the Regents Canal near Kings Cross in London and provides the strategic direction for the whole organisation. DMI is ranked as one of the most cost-effective non-profit organisations in the world by The Life You Can Save.