Millets are known for their nutritive value: they are high in protein, dietary fibre, micronutrients and antioxidants. Millets are also drought-resistant crops that can withstand extreme temperatures and be grown in semi-arid regions with poor soils. In India, the area sown to millets has declined for decades and production of millets is less than 20 million tonnes as compared to over 200 million tonnes of cereals. From the late 1990s, the M. S. Swaminathan Research Foundation (MSSRF), based in south India, began a set of interventions in the Kolli hills block, Namakkal district, Tamil Nadu, to conserve millet biodiversity and expand the production and consumption of millets. This paper begins by describing the basic interventions and the impact pathways from these interventions to outputs, outcomes and impact. It then attempts to provide evidence for each of the impact pathways drawing on different types of evidence gathered over the last 25 years of grassroots activities. The paper argues that reversing the decline in millet cultivation is feasible.