Plants and animals that interact through ecological process, such as seed dispersal, provide critical regulating ecosystem services in tropical forests. They are also essential subsistence and cultural resources for local communities. However, these ecological and ethnobiological interactions are increasingly disrupted by anthropogenic pressures. Ecological networks have been examined to identify species which play disproportionate roles in maintaining community functioning and stability, yet ecologically important species may not necessarily important in human use systems. Here, we compiled one ecological network based on plant-animal seed dispersal interactions, and two ethnobiological networks representing the use-value interactions between local people and plants, and between people and animals in northwestern Madagascar. Ecological data were obtained through behavioral observations and fecal analysis of frugivores, whereas ethnobiological data were collected through structured interviews with local residents. We then estimated the relative importance of each animal and plant species within each network. The ecological network comprised 14 animal (four primates, two rodents, one other mammal, four birds, and three reptiles) and 48 plant species (23 threatened and 25 least-concern species), which were linked to nine animal-use and nine plant-use categories in the ethnobiological networks. In animals, ecologically important and ethnobiologically important species showed little overlap. While an endemic primate, Eulemur fulvus, was the most important seed disperser, an invasive mammal, Potamochoerus larvatus, held the highest use value for food, magical, and breeding. Several plant species possessed high importance in both networks, but the most ecologically significant species differ from the most useful one. Furthermore, least-concern plant species tended to have higher ecological and human-use importance than threatened species. Our findings highlight the need to integrate both ecological and ethnobiological perspectives for feasible forest management.