The Lycopodiaceae is a family of homosporous Lycopsids, presently consisting of 16 genera grouped in three subfamilies, mainly of Neotropical distribution. As part of floristic surveys in Sothern Cone of South America, a revision of Lycopodiaceae in Uruguay is presented. The Lycopodiaceae are represented by eight species, disclosed the first report of Lycopodiella geometra and the confirmation of the presence of Phlegmariurus reflexum in the lycophyte flora of the country, the last one constitutes a novelty of genus level for Uruguayan flora. A dichotomous key, descriptions, maps of distribution and notes on ecology of all taxa of Lycopodiaceae registered for Uruguay are presented and discussed. The populations of Diphasiastrum thyoides, Lycopodiella tupiana,Lycopodium clavatum and Phlegmariurus reflexus in Uruguay represent the austral limit of the distribution of the species.