This family is made up by parasitic wasps of small, medium to large (± 165 mm, including ovipositor or pseudo-ovipositor) size. The colour of the body is variable, just as the body form. The braconids are wanting the distal m-cu cross-vein in the fore wing (except Apozyginae, and some aberrant specimens of e.g. Histeromerinae) and the basal cell of the hind wing does not reach beyond the base of the marginal vein (R1). Few species have wings with a very narrow costal cell present to at least the distal half, and in some species a minute cell occurs at the basal end of the pterostigma. In many genera a vein 1-SR+M of fore wing is present. Several forms are apterous. Many small species have a reduced number of antennal segments, sometimes as few as 11, in contrast to the normally many segmented other genera. The tergites number 2 and 3 of the metasoma are immovably fused, but weakly scleritized in Aphidiinae.
The larvae of the Braconidae have 13 body segments, and in the first instar, the head is often large and sclerotized. The larvae feed gregariously or solitarily on or in a large range of hosts, especially lepidopterous and coleopterous larvae (see pl102), but in some subfamilies adults are parasitized. Parasitising on many pest insects makes this family an important biological control applicant. They occur worldwide, but not in extreme environments.