Clinical diagnoses of depression, self-reported negative emotions, and personality traits have been associated with both the development and progression of coronary heart disease (CHD). This article focusses on negative affectivity (the tendency to experience negative emotions) and social inhibition (the tendency to inhibit self-expression in social interaction) in CHD patients. Two independent samples of patients with CHD were included in this study. Both empirical and internal-structural criteria were used to devise a brief self-report measure comprising an eight-item negative affectivity and an eight-item social inhibition scale in Sample 1 (N=400). These scales were internally consistent (α=.89 and .82), stable over time (three-month test-retest reliability=.78 and .87) and were validated against standard personality scales. CHD patients with a “distressed” personality (Type-D) report high levels of negative affectivity and social inhibition; accordingly, this self-report measure was termed Type-D Scale-16 (DS16). Previous research showed that Type-D was associated with cardiac events and incidence of cancer in patients with CHD. Type-D as measured by the DS16 was associated with depressive affect and symptoms, stress, poor self-esteem, dissatisfaction with life, and low positive affect in Sample 2 (N=100) of the present article. It is concluded that research on CHD should focus on affective disorder, specific negative emotions, and global personality traits, and that the DS16 is a practical, sound research tool that can be used to assess Type-D.