Nearly worldwide, including Antarctica, primarily in temperate latitudes and at higher elevations in the tropics.
Genus 1, species ca. 90 (6 in the flora).
Although W. R. Buck and R. R. Ireland (1985) included only the genus Plagiothecium in Plagiotheciaceae, several bryologists (E. Nyholm 1954–1969; A. J. E. Smith 1978; Lin S. H. 1984; L. Hedenäs 1989b, 1995; N. Pedersen and L. Hedenäs 2002) have included other genera, especially some of those in Hypnaceae, in the family. Plagiothecium undulatum has been removed to Buckiella and placed in Hypnaceae (R. R. Ireland 2001).