Background: The relationship between impulsivity and nonsuicidal self-injury (NSSI) has been revealed in several mental disorders other than phobias. Objectives: The purpose of this study was to examine the relationships among impulsivity, anxiety sensitivity, and NSSI characteristics in patients with phobias, and to compare these relationships with healthy controls. Methods: The sample of this study consisted of outpatients (n = 109) who had been diagnosed with social phobia, agoraphobia or simple phobia in addition to healthy individuals (n = 51) serving as the control group. Data collection tools were the socio-demographic form, the Barratt Impulsivity Scale (BIS-11), the Inventory of Statements About Self-Injury (ISAS), and the Anxiety Sensitivity Index (ASI-3). Results: Mean BIS-11 and ASI-3 scores in the social phobia and agoraphobia groups were found to be significantly higher than those in the control group. In addition, a positive correlation was found between ISAS and cognitive anxiety sensitivity scores in the agoraphobia and simple phobia groups. Discussion: The study revealed a positive correlation between cognitive anxiety sensitivity and NSSI in both the agoraphobia and simple phobia groups. The results of this study indicate that anxiety sensitivity may play a regulatory role between impulsivity and NSSI in some sub-groups of phobia.