The mountains interior of Sri Lanka is one of the world's great tea-producing areas. The labour force on the tea estates consists of a population which has migrated from Tamil Nadu, in southern India, over the last one hundred years. This migrant population is known as 'Indian Tamils' and is largely drawn from the two largest Harijan castes of agricultural labourers in Tamil Nadu. On the now government owned estates, they have formed a kind of industrial proletariat, living in long estate line housing where each family has one or two rooms. The women, who are the tea pickers, work longer hours than do the men. The Indian Tamils have been characterized by markedly higher mortality than the indigenous population (Sinhalese, Sri Lankan Tamils and Moors). This paper reports a research program which was carried out in 1987 and which employed both anthropological and demographic survey techniques in an attempt to explain these higher mortality levels. The research identified the origins of higher mortality, both in limited access to health provision and in the social characteristics and economic circumstances of the community.