Eradicating poverty and halting deforestation are two of the Sustainable Development Goals. Eco-tourism is considered a win-win strategy that can increase income and preserve forests. However, there are no well-identified impact evaluations of both variables at the same time. Seventy-six municipalities in Colombia were randomly assigned to either a control group or a treatment group that received ecotourism promotion. I estimate the socio-economic and environmental effects of nine months of treatment using an ANCOVA specification that controls for baseline individual outcomes. In treated municipalities, I find an increase of 30% in the number of tourists and 16% in the number of workers. However, there are no statistically significant effects on business profits, poverty, or household income. At the same time, I do find a reduction of 100% of deforestation alerts around treated eco-tourism sites. These results illustrate the importance of economic opportunities for local communities in order to preserve forests.