Objective: The purpose of this study was to see whether negative interaction is associated with an increased risk of having heart disease. In the process, an effort was made to see if older people in lower socioeconomic status (SES) groups were more vulnerable to the potentially deleterious effects of interpersonal conflict than upper SES elders. Methods: Interviews were conducted with a nationwide sample of older adults at three points in time. Survey items were administered to assess exposure to negative interaction, SES, and whether study participants had heart disease. Results: The findings reveal that negative interaction is associated with an increased risk of heart disease for lower SES elders only. Moreover, the data suggest that the pernicious effects of negative interaction on heart disease take between 2 and 4 years to become manifest. Discussion: The findings underscore the role played by interpersonal relationships in the etiology of heart disease.