The present monograph treats the moss family Amblystegiaceae in the neotropical area. The family is most widespread in temperate areas and is chiefly distributed at higher altitudes in the tropical and subtropical zones. Because of this, its diversity in the Neotropics is highest in the Andes, especially in the Colombian-Venezuelan area, the Mexican and Guatemalan highlands, and on Hispaniola. Representatives 20 genera are known from the area, including a total of 42 species. One species is described as new. Seven Amblystegiaceae species are endemic to the neotropical area. Most of the members of the family occur in at least temporarily more or less wet or humid habitats, although exceptions occur.