Research carried out to assess the impact of open-pollinated Tomato leaf curl virus(ToLCV)-resistant tomatoes and hybrids on the livelihoods of resource-poor farmers in Southern India is described and discussed.Three high-yielding ToLCV-resistant tomato varieties were developed initially using conventional breeding and screening techniques involving inoculation by ToLCV-viruliferous whitefly,Bemisia tabaci.In 2003 and 2004,respectively,these varieties were released officially by the Karnataka State Seed Committee and the Indian Ministry of Agriculture through notification in the Gazette of India.From 2003 to 2005,eleven seed companies bought breeder seed of the ToLCV-resistant varieties and used them to begin breeding F1 hybrids from them.Socio-economic studies carried out to assess the benefits obtained from growing the ToLCV-resistant varieties found that farmers could gain up to 10 times the profit by growing the ToLCV-resistant varieties compared to the pre-existing ToLCV-susceptible varieties.Adoption of ToLCV-resistant tomatoes was also associated with reduced pesticide use.Extra income from tomato sales was prioritised by farmers to pay for children’s education,better nutrition and medicines.In a joint effort with the commercial seed sector in India,a promotional field day was organised in 2007.As well as the three ToLCV-resistant varieties,62 ToLCV-resistant hybrid tomatoes were exhibited during a farmer-field day by 17 commercial seed companies and several public institutes.Tomatoes with ToLCV-resistance are now grown widely in South India and seeds of the three open-pollinated varieties have been distributed to more than 12 countries.In 2007,a conservative estimate of the financial-benefit to cost of the research ratio was already more than 837:1. Research carried out to assess the impact of open-pollinated Tomato leaf curl virus (ToLCV) -resistant tomatoes and hybrids on the livelihoods of resource-poor farmers in Southern India is described and discussed. Thhree high-yielding ToLCV-resistant tomato varieties were developed initially using conventional breeding and screening techniques involving inoculation by ToLCV-viruliferous whitefly, Bemisia tabaci. 2003 and 2004, respectively, these varieties were released officially by the Karnataka State Seed Committee and the Indian Ministry of Agriculture through notification in the Gazette of India. From 2003 to 2005, eleven seed companies bought breeder seed of the ToLCV-resistant varieties and used them to begin breeding F1 hybrids from them. Socio-economic studies carried to assess the benefits obtained from growing the ToLCV-resistant varieties found that farmers could gain up to 10 times the profit by growing the ToLCV-resistant varieties compared to the pre-existing ToLCV-susceptib le varieties. Adoption of ToLCV-resistant tomatoes was also associated with reduced pesticide use. Extra income from tomato sales was prioritized by farmers to pay for children’s education, better nutrition and medicines. In a joint effort with the commercial seed sector in India, a Promoted field day was organized in 2007. As well as the three ToLCV-resistant varieties, 62 ToLCV-resistant hybrid tomatoes were exhibited during a farmer-field day by 17 commercial seed companies and several public institutes. widely in South India and seeds of the three open-pollinated varieties have been distributed to more than 12 countries. 2007, a conservative estimate of the financial-benefit to cost of the research ratio was already more than 837: 1.