Recent decades have witnessed an increasing corporate access to and control over natural resources resulting in environmental degradation, inequalities and ill health. Since 1972, oil companies have extracted more than two billion barrels of crude oil from the Ecuadorian Amazon. During this process, millions of gallons of untreated toxic wastes, gas and oil have been released into the environment. Indigenous federations, peasants movements and environmental groups have claimed that contamination has caused widespread damage to both people and the environment. This thesis tells the story of how the relationship between local organisations and research institutions developed around an epidemiological study constructed to address communities' concerns. Local organisations set the agenda of the research: they were involved in the hypothesis formulation, consulted in each step during the study and responsible of the dissemination of the findings. This process is known as popular epidemiology. The epidemiological study examines the impacts of oil development practices on the environment and health of residents living in the proximity of oil fields. These residents were exposed to high concentrations of oil chemicals in water used for drinking, washing and bathing. The study suggested a higher risk of spontaneous abortions (POR: 2.47; 95% CI: 1.61-3.79) and adverse health effects such as skin mycosis, itchy nose and sore throat (p<0.05) among women living near oil fields. An excess of cancers among the male population was found in a village located in an oil producing area. Practical and personal issues and dilemmas faced during the research process are discussed with emphasis on the communication and dissemination of the findings. The thesis concludes the need of alliances between communities and researchers in order to protect health and environment. Popular epidemiology is an essential approach for public health researchers to reaffirm their roots in improving public health as a primary value.