Among tourists, there is recently a growing interest in the environment and enjoying the natural world. This study analyzed the motivations and segmentation of the demand for ecotourism, using functional theory as a reference point. Empirical analysis was carried out in Santay National Recreation Area, Morro Mangrove Wildlife Refuge, and Samanes National Recreation Area. The sample included 382 surveys, obtained in situ using the simple random sampling method. Factorial analysis and non-hierarchical segmentation were performed to analyze the data. The results indicate that there are several motivational dimensions in ecotourism, including self-development, interpersonal relationships and ego-defensive function, building personal relationships, escape reward, and nature appreciation. We also identified three different segments of ecotourists based on their motivations—nature, multiple motives, and reward and escape—as well as the characteristics of the different segments. The present investigation will help public institutions and private companies improve their tourism offerings and develop more efficient marketing plans.