The present research extended and tested a motivational model of anger and aggression, derived from self-determination theory. It was hypothesized that control-oriented parents would exhibit more ego defensiveness, feel more pressure, and thus report higher levels of sport parental anger and aggression. Conversely, autonomy-oriented parents were predicted to experience less ego defensiveness, feel less pressure, and thus report lower levels of sport parent anger and aggression. Participants were 340 parents of youth soccer players (boys and girls ages 8–16). The majority of participants reported experiencing anger and responded with varying levels of aggression. The results provide strong support for the hypotheses and suggest that control orientation determines parents' ego defensiveness, which in turn leads to anger and aggressive spectator behavior.