Mitotic karyotypes of five species of tephritid fruit fly parasitoid (Hymenoptera: Braconidae) belonging to the three genera, Psyttalia, Diachasmimorpha and Fopius, are described. The haploid chromosome numbers (n) of the three genera are distinct, i.e., Psyttalia n = 17, Diachasmimorpha n = 20 and Fopius n = 23. The species within each genus share the same haploid chromosome number but the chromosomes differ in size and shape: 7 metacentric (M), 7 submetacentric (SM) and 3 subtelocentric (ST) chromosomes in P. fletcheri compared with 6 M, 9 SM and 2 ST in P. incisi; and 5 M, 13 SM and 2 ST in D. longicaudata compared with 6 M, 12 SM and 2 ST in D. dacusii. F arisanus showed 5 M, 13 SM and 5 ST. These karyological data are useful for cytotaxonomy and contribute to a better understanding of the chromosomal evolution of these fruit fly parasitoids. Genetics; Cytogenetics; Chromosomes; Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Land zones; Oriental region; Eurasia; Asia Tephritidae; Hymenopteran parasites; Diachasmimorpha; Fopius & Psyttalia; Parasitoid karyotypes; Thailand; Karyotypes of hymenopteran parasites Diachasmimorpha dacusii; Diachasmimorpha longicaudata; Fopius arisanus; Psyttalia fletcheri; Psyttalia incisi (Braconidae ); Karyotype; Parasitoids of dipteran hosts; Dipteran hosts; Tephritidae; Thailand; Karyotypes of dipteran host parasitoids none