This secondary analysis used the five-factor model of personality to examine personality traits in four samples of patients with chronic disorders. Profiles of personality traits differed across disorders. Although participants with psychiatric disorders and participants with HIV/AIDS had similar patterns of personality traits, patients with psychiatric disorders were more extreme on all traits except agreeableness. Patients with hyperlipidemia and those who had cardiothoracic transplants had similar patterns. Nurses and researchers need to consider personality traits that drive patterns of behavior in designing more effective ways to promote better health and manage disease.