Aphid parasitoids are important bio-control agents, being used in aphid pest management in the field as well as in greenhouses worldwide. Over 400 species of parasitoids are described worldwide and most of them are being used as a basis of integrated pest management (IPM). In Pakistan, only 30 species of aphid parasitoids were reported; out of those 11 species were recorded from Potohar region of Punjab Province of Pakistan. Keeping in view this low level of basic research on these important insects, mummified aphids, adult parasitoids and hyperparasitoids were collected from various localities of Punjab during 2005-08. A total of 10827 parasitoid individuals were collected consisting of 30 species in 8 genera belonging to subfamily Aphidiinae along with 58 new trophic associations and 184 new locality records. Nine species namely: Aphidius gifuensis, Aphidius hortensis, Aphidius hieraciorum, Aphidius phalangomyzi, Aphidius salicis, Aphidius sonchi, Binodoxys basicurvus, Binodoxys rubicula and Binodoxys angelicae are recorded for the first time from Pakistan. A species, Trioxys aridunivercena sp. nov. is described as a new to science record. In addition, a total of 1257 hyperparasitoid individuals were collected consisting of 6 species in 6 genera from 3 subfamilies along with 19 new trophic associations and 51 new locality records. One species, namely Alloxysta carinata is a new record for Pakistan. Host plants and primary parasites of A. carinata are new scientific records. Two species, Phaenoglyphis punjabensis sp. nov. and Dendrocerus rawalena sp. nov. are new scientific records. Identification keys for all recorded species have been prepared. Species are illustrated by their valid names, synonyms, measurement of various body parts, xviitritrophic association, comparison of characters from published descriptions for new records to country and comprehensive characters description for new science specimens has also been provided. The known distribution of all the species is also updated. A map is provided for the distribution of each of them. Biology of most common and voracious parasitoids is given. As Diaeretiella rapae is the most common parasitoid so its general biology including study of various life stages along with some biological parameters like copulation time, pre-mating time, oviposition time and adult longevity have been given. Biological parameters like mummy colouration, position and shape of emergence hole of parasitoids and hyperparasitoids have been given for two aphid species namely, Aphis gossypii and Aphis fabae. Sex ratio of field collected populations of the parasitoid species like Diaeretiella rapae, Aphidius transcaspicus, Aphidius uzbikistanicus, Aphidius avenae, Aphidius smithi and Binodoxys anglicae emerged from the mummies of various species of aphids have been determined and was found female biased. Sex ratio of all recorded parasitoids and hyperparasitoids species are calculated and found to be female biased. A list of trophic associations of host plants, aphids, parasitoids and hyperparasitiods has been provided. Presence and absence of various aphid parasitoids and hyperparasitoids in various localities of Punjab is also tabulated for future reference.