Anti-depressants are commonly used to treat major depression and post-traumatic stress disorder. 17% of women experience major depression during pregnancy, where up to 10% of pregnant women use antidepressants. 20% these women use Prozac (fluoxetine) to treat major depressive symptoms, which crosses the placental barrier and is present in breast milk. Little is known about how exposure to developmental fluoxetine affects adulthood behaviors such as agonistic and submissive behaviors, especially in females. Furthermore, the effects of developmental fluoxetine exposure on aggression and avoidance in Syrian hamsters have not been studied. Therefore, we explored how prenatal and perinatal exposure to fluoxetine affects adulthood aggression and avoidance in male and female Syrian hamsters. Dams were given fluoxetine via drinking water 7 days prior impregnation. Fluoxetine administration continue until offspring reached postnatal day (PD) 12. The offspring were weaned and group-housed at PD 25 and single-housed at PD 60. Animals were handled one week prior to behavioral testing. The following week, animals were tested for aggression in a neutral arena with a non-aggressive stimulus hamster of the same sex. Another group of hamsters were tested for avoidance behavior in a neutral arena 24 hours after social defeat. Duration of aggression and avoidance were quantified. There was no main effect of sex or drug nor was there an interaction. Therefore, we reject our hypothesis of prenatal and perinatal exposure to fluoxetine will affect aggression and avoidance in male and female Syrian hamsters. These findings may be due to a ceiling effect in Syrian hamsters, where the subtle effects of developmental fluoxetine exposure were not observable.