Based on five months of participant observation among health workers in rural Malawi, Central Africa, this master thesis examines how Health Surveillance Assistants (HSAs) with eight to ten weeks of official training handle different traditions of medical knowledge in their work. Main focus is put on mobile health clinics for children under five years of age, so-called Out Reach, U/5 clinics. With this system, basic child-health services are made available on a monthly basis in remote villages by HSAs on bikes. They conduct key HSA tasks like health talk and vaccination in schoolyards, by communal water pumps and the like. Starting from empirical data produced by attendance at fifty-four such U/5 clinics and in a myriad of other settings, the analysis draws on theory from the anthropology of knowledge, medical anthropology and regional studies. The enquiry contributes to the understanding of how child vaccination programs are realized, in addition to contributing to the anthropological literature on knowledge management. Social anthropology student and nurse, Kristin Alfsen, argues that the HSAs mediation between individual, local, national and international views on health and their locally adjusted, varied and pragmatic methods of knowledge management contribute to the high vaccination coverage found in Malawi, compared with other poor countries. By studying the HSAs positions of multi-relations, and the knowledge management that takes place at interfaces they thereby are involved in, this thesis also deals with issues of power, resistance and trust. Additionally, HSAs and the Wisdom to Handle Knowledge: A Study of Health Surveillance Assistants. Work in Rural Malawi 2010 reveals some of the harsh effects of severe poverty on individuals and communities, along with related vulnerabilities in the national child vaccination program.