An ethnobotanical survey was carried out among a campesino community in a Costa Rican montane cloud forest. Campesino families were interviewed about how they used indigenous and introduced vascular plants along an altitudinal gradient (2000–3000 m). From a total of 590 species known in the area, 23.8% of 189 useful plant species were used for medicinal purposes, 39.7% for food, and 24.3% for construction (timber) or as combustibles (fuelwood, charcoal). Less important uses included dye, ornament (ecotourism), fodder, gum, oil, and poison. A total of 61.9 % of the plants were used for one purpose only. The introduced and exotic woody species Cupressus lusitanica and Eucalyptus globulus showed the highest diversity in types of use (7), together with the native Alnus acuminata. Trunks (53%) and fruits (47%) were the main plant organs used, followed by leaves (33%) and branches (30%). Over 27.5% of all plants were used on a daily basis, while 34.9% were used occasionally. About 11.6% of the species were rarely used. At present, use of indigenous species is becoming less common; the trend is to favour introduced and economically important species. In the short or medium term, local knowledge of medicinal plants will probably disappear in this rural community that is undergoing modernisation, with a focus on new undertakings such as fruticultural export, rainbow trout hatcheries, and ecotourism.