Most ecotourism studies in the past have examined tourist perceptions on tour guides' performance. However, there has been little research investigating ecotourism in relation to the practices of guided tours. This paper, therefore, aims to examine tourist perceptions of different guided ecotourism tours and their contribution to sustainability. Data were collected from three companies with six guided tours through tour observation, interviews and surveys in the southern region of Thailand. For the survey, data were collected from 183 voluntary respondents who joined the guided tours. Content analysis, descriptive statistics, and one-way ANOVA were used to analyze the data. The results indicate that certain ecotourism principles were implemented in the guided tours. In particular, tourists perceived that the practices of guided tours and their contribution to the local area were different from one another, depending on the type of tour. Not only do the findings of the study provide new insights into the typology of ecotourism activities, but they also yield a better understanding of the key factors contributing to tourists' ecotourism experience and local benefits. Recommendations in relation to tour design, tourist activities and staff training are discussed to enhance ecotourism-related benefits for local communities.