Oxytocin (OT) not only modulates positive social interactions but also affects negative ones. Several studies have established a link between OT and aggression. However, they also resulted in an inconsistent picture and showed methodological issues. The current studies aimed to address these lacks and test the hypothesis that OT increases provocation-induced aggression in people low in anxiety. Therefore, two studies with 56 males (Study 1) as well as 40 females and 24 males (Study 2) were conducted. After responding to a trait anxiety questionnaire, participants self-administered OT or a placebo. Thereafter, provocation was manipulated by rejecting vs. accepting (Study 1) or insulting vs. accepting (Study 2) the participants by real human counterparts. Aggressive behavior was quantified by measuring how much hot sauce (Study 1) or unpleasant blasts of white noise (Study 2) participants delivered to their opponents, using two classic aggression paradigms. Both studies provided evidence that OT promotes aggression in response to provocation in low anxiety people which was not the case with no provocation or in high anxiety people. These findings confirm the idea that OT can be involved in the creation of aggressive behavior when accounting for situational and dispositional features.