Ixodiphagus wasps (Hymenoptera: Encyrtidae) have been known as parasitoids of ticks since the beginning of the 20th Century. Currently, there are seven recognized species: Ixodiphagus texanus Howard, Ixodiphagus hookeri (Howard), Ixodiphagus mysorensis Mani, Ixodiphagus hirtus Nikolskaya, Ixodiphagus theilerae (Fielder), Ixodiphagus biroi Erdos, and Ixodiphagus sagarensis (Geevarghese). These wasps have been found parasitizing ticks belonging to the genera Ornithodoros, Amblyomma, Dermacentor, Hyalomma, Haemaphysalis, Ixodes, and Rhipicephalus. Parasitism by wasp parasitoids results in direct mortality of the tick hosts and appears to have potential for controlling them. This article reviews the taxonomy, life cycle, seasonality, host range and geographical distribution of these wasps, and their potential application to tick control.