A total of 1878 birds of 217 species were examined for the presence of fleas in Costa Rica during 2004, 2009, and 2010. Altogether 58 specimens of fleas belonging to four species of the family Ceratophyllidae were collected from 43 individuals of 27 bird species. The fleas Dasypsyllus (Dasypsyllus) gallinulae perpinnatus (Baker 1905), which were the most common, were found in 25 bird species. Dasypsyllus (Neornipsyllus) stejnegeri (Jordan 1929) and Ceratophyllus (Ceratophyllus) niger Fox, 1908 were found in three and one bird species, respectively. Six Plusaetis equatoris (Jordan 1933)-like fleas were collected from one individual of the timberline wren Thryorchilus browni (Passeriformes, Troglodytidae).