Mexico, West Indies, Central America, South America, s Asia, Africa, Indian Ocean Islands, Pacific Islands (Hawaii).
Genera 2, species ca. 1400 (1 genus, 2 species in the flora).
Molecular phylogenetic and morphologic data show that Begoniaceae comprise two genera: the monotypic, Hawaiian endemic Hillebrandia Oliver (H. sandwicensis Oliver), and pantropical Begonia (W. L. Clement et al. 2004; L. L. Forrest et al. 2005). Although present in New Guinea, the family is natively absent from Australia. The Hawaiian Archipelago is the only group of Pacific Islands where the family is native. The relationships of Begoniaceae are with the Cucurbitales, sister to Datiscaceae in the narrow sense (Angiosperm Phylogeny Group 2009).