Nineteen species of Trouessartia are known from swallows (Hirundinidae) of the Old World. Each species (one exception) can be assigned to one of two distinct species group, the appendiculata group and the minutipes group. ln general, each hirundinid genus harbors one species from each of the groups. The species of the minutipes group are (re)described: T. amplivasa, n. sp., from T. Cecropis species; T. botulifera, n. sp., from Ptynoprocne fuligula; T. gabonica, n. sp., from Pseudhirundo griseopygia; T. juliettae, n. sp., from Phedina borbonica; T. microcaudata, Mironov, from Hirundo species; T. minutipes (Berlese), from Delichon urbica; T. paludicolae, n. sp., from Riparia paludicola; T. quarta, n. sp., from Hirundo rustica and T. ripariae, from Ripaia riparia. Hirundo rustica supports populations of T. microcaudata and T. quarta but rarely do they coexist on an individual host