Psychodopygus wellcomei n. sp. (Diptera, Psychodidae) is described from southern Pará, Brazil. The male genitália are complex and can easily be distinguished from those of closely related species. The females are similar to those of other members of the squamiventris group, but are characterised by the nature of the spermathecal ducts, the number of vertical teeth in the cibarium, and the length of 3rd antenal segment. The authors confirm that material from Amapá, identified by previous workers as P. squamiventris, belongs to a separate species, P. maripaensis. The authors consider that P. wellcomei may be important as a vector of cutaneous leishmaniasis to man, as it was the commonest anthropophilic species in a highly endemic area and bit man avidily both at night and during the day.