Ecosystem services (ESs) can be defined as the values and benefits provided by ecosystems for human well-being. The main characteristic of ESs is that they benefit people. Agriculture is an important provider of ESs for society, culture, the environment and the economy. In mountain areas, agriculture embodies different functions. This work assesses the value of ESs provided by mountain farms according to mountain tourists’ opinions, using a Choice Experiments (CEs) approach and quantitative surveys. CEs allow multiple scenarios with different attributes associated with monetary values that respondents had to choose. The sample comprised 840 mountain tourists, interviewed through an online survey in April 2020. The main results show that the ESs provided by agriculture and preferred by tourists are the maintenance of pastures and grazing, which are considered to shape the mountain landscape and provide for cultural and environmental ESs. Moreover, biodiversity conservation is another one of the most appreciated attributes, being fundamental for protecting the environment. A noticeable result is the importance associated with the ES provided by agriculture related to the regulation of hydrogeological assets, meaning that the awareness of the hydrogeological instability of mountain slopes is widespread and that tourists are sensitive to this topic.