Relationships between serum cholesterol and suicidal behavior have been reported. As suicidal behavior is common in cocaine dependence, we looked for a relationship with serum cholesterol. To do this, we compared 57 cocaine-dependent patients who had attempted suicide with 111 cocaine-dependent patients who had never attempted suicide for their admission total serum cholesterol levels. We found that there were no significant differences between cocaine-dependent patients who had or had not attempted suicide in their total serum cholesterol levels. Also, there were no significant correlations between total serum cholesterol levels and scores on the Barratt Impulsivity Scale. Thus, admission total serum cholesterol does not appear to be clinically useful in the assessment of suicidal behavior in cocaine-dependent patients.