Although stressful life events can trigger adverse mental health outcomes, many people will not develop symptoms of depression or Posttraumatic Stress Disorder (PTSD), leading researchers to seek out factors that influence the relationship between life events and emotional responses. PTSD appears to be more likely following interpersonal traumas compared to non-interpersonal traumas, but the reasons for this relationship are unclear. The current study examines whether event significance mediates the relationship between event type (interpersonal or non-interpersonal) and PTSD and depressive symptoms in a sample of 314 college students. Perceived importance was higher for interpersonal events, and we found support for a mediational role of event importance in the relationship between event type and mental health symptoms. Findings suggest that the importance of an event to one's identity might underlie the relationship between event characteristics and mental health outcomes and be a salient target for prevention and treatment efforts.