A new Nearctic species of the fungus gnat genus Palaeodocosia Meunier was discovered in western Michigan. Two adult males flew to a Malaise trap in jack pine (Pinus banksiana Lambert) forest in early December, after the first snows of late autumn had melted. This brings the total number of known extant Palaedocosia species to four. Two are Palaearctic [Palaeodocosia alpicola (Strobl) and Palaeodocosia flava (Edwards)], one is Holarctic [Palaedocosia vittata (Coquillett)], whereas the new species is Nearctic only. Adult females and juveniles of Palaeodocosia michigana Taber are unknown.