The present study investigated the association between nonsuicidal self-injury characteristics, functions, and the UPPS-P impulsivity-related traits in high-school students using self-report questionnaires. More than 17% of the 613 students engaged in at least one type of NSSI behavior. Compared to male students, female students engaged more often in cutting and less in head banging. All NSSI behaviors were significantly related to Negative and Positive Urgency, that is, the tendency to act impulsive in the presence of negative/positive affect. Interactions between different UPPS-P impulsivity dimensions did not increase the percentage of explained variance in the different NSSI behaviors. Furthermore, severe cutting was negatively related to Lack of Premeditation. Different NSSI functions showed differential relationships with the five UPPS-P impulsivity dimensions.