Although the effects of serum total cholesterol and other lipids have been implicated as a predictor of suicidal behavior in major depression, the role of cholesterol level on suicide risk for panic disorder patients is not considered as a biological marker in the literature. In this study, we examined the relationship of suicidality with serum cholesterol concentration in panic disorder. The subjects of the study were 10 suicidal panic disorder patients, 19 nonsuicidal panic disorder patients, and 15 normal control subjects. The suicidal patients with panic disorder had lower serum total cholesterol and low-density lipoprotein (LDL) levels than normal control subjects. These findings suggest that there may be an association between suicidality and low serum cholesterol levels in panic disorder. We also discuss the possible role of serotonin in the brain in the relationship of suicidal behavior or ideation with low cholesterol concentration in panic disorder. © 2004 Elsevier Inc. All rights reserved.