Background: Clinical and empirical research evidenced a complex link between pathological narcissism and the suicidal process in adulthood. Given the relevance of suicidality and the peculiar narcissistic vicissitudes of adolescence, the proposed research investigated the relationship between pathological narcissism analyzed from the multi-dimensional perspective of the Diagnostic Interview for Narcissism (DIN) and suicidal ideation conducted in a sample of Italian Adolescents. Methods: One hundred and three Italian male and female adolescents between 12 and 18 were administered the DIN, SCIDII, CSSRS, and Kiddie-SADS with six months follow-up. Results: The correlation, t-test, multiple regression analyses evidenced the association of narcissistic affective states and mood with both suicidal ideation and lethality of conduct. The increase in the dimension of grandiosity is associated with the passage to potentially highly lethal suicidal gestures. Conclusions: Suicidal ideation and conduct seem to serve the function of restoring a sense of control and self-esteem in narcissistic individuals experiencing a state of affective dysregulation. Narcissistic pathological functioning seems to play an important role in the adolescent suicidal process, quite like adulthood. Assessing an adolescent`s narcissistic functioning may provide useful clinical information in understanding and managing the suicidal risk in this phase of life.