Learning of olfactory and gustatory cues occurs throughout the adult stage of parasitoids, particularly during host location and patch exploitation. A loss of learning capacities could affect both the whole host–parasitoid system and the wasps' reproductive success. We analysed the effect of low-temperature exposure on learning, patch exploitation strategies and patch-leaving rules used by Anaphes victus (Hymenoptera: Mymaridae). Females were stored 0, 3, 6 and 12 weeks at 4°C at the second larval instar. After emergence, females were offered three successive patches containing 16 hosts, of which 0, 50 and 100%, respectively, were parasitized, and their foraging behaviours were recorded. Cold-exposed females oviposited fewer eggs, seemed less able to learn external marks (or did not use their learning capacities), oviposited more in already parasitized hosts and used different patch-leaving rules to control females. The degree of the change in behaviour was positively correlated with the duration of cold exposure. Low-temperature exposure thus affected the reproductive success, expression of learning, host discrimination ability and patch-leaving decision rules of the parasitic wasps. We discuss the implications of these effects on the pattern of patch exploitation for biological control and field situations.