This article explores the scientific and entrepreneurial incentives for malaria research in the tea plantations of north Bengal in colonial India. In the process it highlights how the logic of ‘location’ emerged as the central trope through which medical experts, as well as colonial administrators and planters, defined malaria research in the region. The paper argues that the ‘local’ emerged as both a prerequisite of colonial governance as well as a significant component of malaria research in the field. Despite the ambiguities that such a project entailed, tropical medicine was enriched from a diverse understanding of local ecology, habitation, and structural modes of production. Nevertheless, the locality itself did not benefit from anti-malarial policy undertaken either by medical experts or the colonial state. This article suggests that there was a disjuncture between ‘tropical medicine’ and its ‘field’ that could not be accommodated within the colonial plantation system.