Anger and low self-esteem characterize borderline individuals, yet little is known about their role and impact in the presence or absence of self-injury behavior. The present study aimed to investigate the impact of anger and self-esteem in borderline patients and whether these variables distinguish these patients with and without self-injury. Patients were recruited from a psychiatric service and were evaluated for self-esteem and anger. Additionally, impulsivity and symptoms were assessed. Two groups were compared, one with self-injurious behavior (n = 18) and another one without it (n = 23). Those who injure themselves seem to have a lower self-esteem (p < 0.001), yet the strengthening of self-esteem seems to have different outcomes, according to the presence or absence of self-injury. Anger and self-esteem seem to influence the severity of diagnosis, but only in patients who self-injure. Anger and self-esteem may influence borderline patients differently according to the presence or absence of self-injury.