A study was initiated on Taxonomy of Chalcididae of Khyber Pakhtunkhwa, Pakistan. Diverse ecological zones were surveyed at different times and seasons of the year. Most of the collection was done from grasses and low vegetation during 1998-2014. Some of the species were reared from their hosts in laboratory. Two hundred specimens of Chalcididae were examined. It was found that 26 species belonging to 11 genera under four subfamilies are occurring in the area. The subfamilies include Haltichellinae, Chalcidinae, Dirhininae and Epitraninae. Subfamily Haltichellinae comprises of genus Antrocephalus Kirby, Hockeria Walker, Kriechbaumerella Dalla Torre, Neochalcis Kirby, Neohybothorax Nikol’skaya, Psilochalcis Kieffer and Proconura Dodd & Girault. Genus Antrocephalus Kirby include two species viz., Antrocephalus mitys Walker and A. nicus Narendran; genus Hockeria Walker is represented by two species viz., Hockeria argentigera Holmgren and H. nikolskayae Husain & Agarwal; genus Kriechbaumeralla Dalla Torre consist of Kriechbaumerella ayyari (Gahan) and K. kala Narendran; genus Neochalcis Kirby comprises of only one species, Neochalcis breviceps (Masi); genus Neohybothorax is represented by one species, Neohybothoax hetera (Walker); genus Psilochalis Kieffer is also represented by one species Psilochalcis carinigena (Cameron) and genus Proconura Dodd & Girault comprises of one species Proconura minusa Narendran. Two genera namely, genus Brachymeria Westwood and genus Chalcis Fabricius were found in Subfamily Chalcidinae. Genus Brachymeria Westwood was found to be the most speciose genus with 8 species including Brachymeria alternipes (Walker), B. apicicornis (Cameron), B. jambolana (Gahan), B. marginiscutis (Cameron), B. minuta (Linnaeus), B. podagrica (Fabricius), B. habui Huseyin Ozdikmen and B. medicina Joseph, Narendran & Joy. Genus Chalcis Fabricius is represented by a single species Chalcis gibsoni Narendran. Subfamily Dirhininae includes one genus Dirhinus Dalman which is represented by five species viz., Dirhinus anthracia Dalman, Dirhinus auratus Ashmead, Dirhinus hesperidum (Rossi), Dirhinus himalayanus Westwood and Dirhinus secundarius Masi. Subfamily Epitraninae contains one genus Epitranus Walker. Two species Epitranus parvidens (Strand) and Epitranus elongatulus (Motschulsky) were found in genus Epitranus Walker. All except H. nikolskayae are new records for Khyber Pakhtunkhwa. Illustrated keys to the genera and species of Chalcididae of Khyber Pakhtunkhwa are provided. Host range, distribution, type material examined and improved description of males and females are also provided. The species were confirmed by comparing them with paratypes available at Bohart Museum of Entomology, University of California, Davis, USA.