Abstract This study examined the relationship between premenstrual exacerbation and suicidal behavior in patients with panic disorder. Twenty-eight patients who reported a premenstrual exacerbation of panic disorder and 42 patients who reported never having an exacerbation were included in the study. The subjects completed a self-rating instrument assessing the 13 DSM-III-R panic symptoms on a 5-point scale (0 = absent, 1 = mild, 2 = moderate, 3 = severe, and 4 = very intense). They also completed the severity scale of the Clinical Global Impression. The Schedule for Affective Disorders and Schizophrenia (SADS) suicide subscale was used to rate the severity of active suicidality. We found that patients with premenstrual exacerbation of panic disorder had higher SADS suicidality scores than patients with panic disorder without premenstrual exacerbation. They were also more likely to be classified as suicidal than the others. It may be that premenstrual exacerbation is a risk factor for suicidal behavior independent of major depression in patients with panic disorder.