Effect of mating status on locomotor activity was examined in females of the parasitoid wasp Nasonia vitripennis (Walker). Mated females were more active than virgin females in both strains of N. vitripennis that were tested and regardless of whether or not the mated female stayed with her mate before testing. Mated females were more active than virgin females when tested immediately after mating and when tested 1 h, 1.5 h, and 2 h after mating. Mated females were still more active than virgin females when both had been allowed to parasitize a host for 2 h. Mated females were not significantly more active than virgin females at 1, 3, and 5 d after mating. Mated females that were allowed to parasitize a host for 3 h before testing were less active compared with those not given a host. Amount of activity was independent of a female’s head width and did not affect a female’s subsequent offspring production. Despite being more active, mated females did not kill more hosts than virgin females. However, among mated females, females that were more active subsequently killed more hosts, whereas this was not true for virgin females. Discussion of relevance to biological control and suggestions for future research are provided.