Oil exploration demands a series of health risks for workers and also for native populations anciently living in remote zones and frequently aisled, where the presence of the Government is absent or precarious. Risks are in both ways: (a) diseases that can be introduced by workers into populations with limited occidental contact, and (b) mainly tropical diseases which circulate in exploration zones and can affect people who enter into these zones. The companies challenge is to develop preventive programs for both situations. The use of vaccinations by personnel who enters into exploration zones, as well as to avoid the entrance of personnel with any kind of health problem is the most utilized and proper strategy in order to prevent the introduction of diseases into these zones. The experience shows us that this strategy works only when the indicated principles are rigorously accomplished, however, it is important to be conscious of the existence of limitations, as it would be the case of the A H1N1 Flu, with no commercially available vaccinations, and with an incubation time that can last up to one week, which would imply that a worker can enter into the zone with no symptoms, but already in the field can present them and initiate a contagious chain. The workers risk to get endemic diseases which circulate in rural areas is a more complex challenge, as they are of diverse nature. In front of this, WALSH is developing a strategy to minimize workers risks, contemplating: (1) educational program in order to inform the workers about the most common diseases in areas where they will be mobilized and measures for individual and collective protection; (2) training to health workers and nurses who accompany the brigades -including brigade chiefs- about diagnosis and treatment (in field conditions) of the more common pathologies in contact zones, as well as a precise definition about the conditions in which patients with any kind of risk must be evacuated; (3) selection of the equipment, consumables, and medicines of the first aid kits, suitable to the working environment; (4) subscription of collaboration agreements with control and prevention programs that are being developed in the zone, as in the case of the control program against malaria (PAMAFRO) which is being carried out in the Peruvian jungle, and allows to optimize its diagnosis, treatment, and preventive measures. This group of measures has determined a decrease of the majority of the diseases -among them, malaria- and has reduced the number of events that mean evacuation. Copyright 2010, Society of Petroleum Engineers.