The purpose of this study was to examine the association between recurrent sleep, panic, and suicidal behavior in panic disorder. We compared the recurrent sleep panickers (N = 33) with other panickers (N = 34), The Schedule for Affective Disorders and Schizophrenia (SADS) suicide subscale was used to rate the severity of active suicidality, We found that recurrent sleep panickers also had a higher percentage of insomnia and comorbid major depression than the others. A multivariate analysis demonstrated an association between recurrent sleep panic and suicidal tendencies in patients with panic disorder. Although recurrent sleep panic alone is not an independent risk factor for suicidal behavior, it may modify the severity of illness in patients with panic disorder. Copyright (C) 1998 by W.B. Saunders Company.