Resumo: The study presents an analysis of the relationship between ecotourism and conservation attitudes held by local community in two biosphere reserves: Los Tuxtlas, Mexico and Maasai Mara, Kenya. Information was collected through a quantitative survey administered by the researcher, open interviews, four focus group discussions, as well as direct observation and participation. It was found that conservation attitudes are determined by different factors, among them, direct and indirect benefits of ecotourism, customs, laws and restrictions. It was also found that ecotourism can generate negative impacts as a result of unintended or wrong actions