An analysis of liverwort diversity in Rio de Janeiro state has been done, with the objective to elucidate the richness and floristic composition of the different formations of the Atlantic Forest, and the influence of the altitudinal gradient on the liverworts. For this, data from literature, herbarium, floristic inventories and data bank of the state's flora were combined. The liverwort flora is composed of 360 taxa distributed among 102 genera and 31 families, emphasizing the importance of the remaining part of Rio de Janeiro's tropical rainforest for the conservation of the liverwort diversity in Brazil. In the state's remaining tropical rainforests 50% of the liverwort flora of the country and 72% of that of the Atlantic Forest are found. The flora is not uniform, presenting differences in species richness and floristic composition in different formations of the state's Atlantic Forest, in addition to a floristic gradient along the altitudinal gradient. The Montane formation has higher species richness (238), number of exclusive taxa (63) and endemics (27), followed by the Upper Montane formation (173, 58 and 21, respectively). Lejeuneaceae stands out as the richest family in all formations, whereas other families are exclusive to certain formations. As is true for mosses, several liverworts appear as diagnostic features of altitudinal belts in Atlantic Forest, corroborating the use of bryophytes as indicators of altitudinal zonation in tropical rainforests.