The current study investigated the influence of exogenous OT and its interaction with endogenous T on brain activity during processing of infant faces, which varied in the intensity of BS. We found a positive effect of drug treatment in the direct comparison of OT versus placebo using the contrast of “baby versus adult target” in the IFJ, but only in the high BS condition. This finding supports the idea that OT may enhance attention to increased BS and may further promote one’s motivation to act. Additionally, we found a positive correlation between selective attention to babies, as indicated by increasing Delta-RTs, and increased activation in the left putamen following OT treatment. Interestingly, this correlation was specific for women with high endogenous T. Collectively, these findings may provide a hint to the neural mechanism by which OT may support the sensitivity for the BS and may counteract the negative effects of T in the modulation of nurturing behavior.