The largest collection studied so far of mosses in Dominican amber is reported here. The collection, in the Smithsonian Institution, consists of 76 pieces of amber containing bryophyte material, with a range of one to seven species of mosses and liverworts per piece. Nearly all specimens could be attributed to extant taxa and a total of 18 distinct moss species were identified in this collection, which raises the total number of mosses known from Dominican amber to 28. Six taxa assignable with some confidence to extant species are reported for the first time from Dominican amber: Calymperes levyanum, Calymperes smithii, Mniomalia viridis, Octoblepharum cylindricum, Orthostichopsis praetermissa, Plagiomnium rhynchophorum. A list of all species of mosses so far known from Dominican amber is given with an indication of their frequency in amber, and present distribution and altitudinal range. Some species are very rare at present and may be approaching extinction today. The main component of mosses so far found from the amber forest consists of species of Leucobryaceae, Calymperaceae, and Neckeraceae. Most species are widespread and found today in the West Indies as well as in Central and South America, thus representing an old stock of neotropical species. The present altitudinal distribution of the species ranges from lowland-submontane to montane, indicating climate changes within the period of amber production. In contrast to the liverworts reported from Dominican amber, the mosses can mostly be attributed to extant species, indicating perhaps a slower rate of evolution than in liverworts. Assemblages of several bryophyte species in amber show the presence of extinct liverworts together with extant mosses, the latter in combinations which are still found today.