Background: Hematozoa of the genus Plasmodium cause malaria in birds, and are frequently found in passerines. They are characterized by particularly small meronts and elongated gametocytes in peripheral blood. Although the disease is not fatal, it affects reproductive success and, therefore, the biodiversity of the birds, so it is a necessity to know the species of birds that are infected. Methods: The presence of Plasmodium in passerine birds were investigated in three locations in the inter-Andean dry forest of the province of Imbabura in Ecuador. Prevalence and parasitaema were determined by light microscopy of blood smears and was confirmed by the indirect immunofluorescence assay (IFA) with a monoclonal antibody that recognizes protein 1 of merozoite surface (MSP-1). Results: The percentage of prevalence and parasitaemia in the bird species captured in the three locations was determined and was related to the elevation and presence of bodies of water in the studied areas. A 100% prevalence was found at the lowest site but decreased with elevation and the absence of nearby water bodies. The IFA test supported the identity of the Plasmodium parasite. Discussion: This study shows that bird species are highly parasitized in the dry forest of Imbabura and underscores the influence elevation and the presence of water as a possible source proliferation of the vector insects. As elevation increases, prevalence and parasitaemia decrease. Besides, we present a useful new diagnostic tool, a monoclonal antibody that recognizes Plasmodium protein MSP-1, which is highly conserved among the species of this parasite.