text: In a tribal village in Kerala, India, local volunteers were trained to work in a programme for the primary prevention of tobacco-related cancers and the secondary prevention of common cancers. They gathered data on the use of tobacco and alcohol in a population of some 19,000 people, and identified one or more warning signals of cancer in 430 persons, who were subsequently examined by physicians. Confirmation was obtained of 10 new cancers, 7 recurrent cancers, 46 oral precancerous conditions, and 58 precancers at other sites. The community's awareness of cancer problems increased and the people learnt about the importance of self-examination in the detection of breast cancer and oral cancer.