One new species of larval Trombidium Fabricius, 1775, T. montenegrinum sp. nov. collected off-host on grasses, is described and illustrated. Descriptions of T. botovicum and T. daunum are corrected. A key to world species of larval Trombidium is presented. Using published records and original data, a checklist was compiled of the terrestrial parasitengone mites of Montenegro. The total number of species recorded from Montenegro up to date is 51 species, in 25 genera and 7 families. Additionally, first records for Montenegro are given for Charletonia krendowskyi Feider, 1954, Marantelophus multisetosa (Zhang & Goldarazena, 1996), Abrolophus stanislavae (Haitlinger, 1986), Erythraeus (Zaracarus) hamedanicus Saboori et al. 2004, Erythraeus (Z.) preciosus Goldarazena & Zhang, 1998 and Johnstoniana parva Wendt et al., 1994.