Generalization is a symptom of many anxiety disorders, and females are 60% more likely to suffer from anxiety disorders than males. We have previously demonstrated that female rats display accelerated rates of contextual fear generalization compared to males; a process driven, in part, by activation of ERb. The current study attempted to determine the impact of estrogens on contextual fear generalization in male rats. For experiment 1, adult male rats were gonadectomized (GDX) and implanted with a capsule containing testosterone proprionate (T), estradiol (E2), dihydrotestosterone proprionate (DHT), or an empty capsule. These data suggest that T attenuates fear generalization in males likely through the aromatization of T into estradiol as animals treated with the non-aromatizable androgen, DHT, displayed significant generalized fear responses. In experiment 2, experiment 1 was replicated with acute injections administered 24 hours before training. Animals treated acutely with E2 injections displayed reduced fear generalization similar to those observed in experiment 1. These data suggest that estradiol modulates fear generalization in a bi-direction, sex-dependent manner.