This cross-sectional study aimed to describe the perception of control over heart disease, and the likely antecedents of this perception, in 340 people with an inherited predisposition to premature coronary heart disease. Dependent variables were self-efficacy and response efficacy. Independent variables were history of heart disease and current symptoms, current cholesterol level, emotional state, and causal attributions. Overall, levels of perceived personal control (self-efficacy) were moderately high and treatment was perceived to be effective (response efficacy). Predictors were having a lower current cholesterol level, not experiencing symptoms of angina, lower anxiety, lower depression, and perceiving chance as less important and cholesterol as more important in causing a potential heart attack. Thus, previous and current experience together with causal attributions and emotional state are related to perceptions of control over heart disease in at-risk patients. These findings highlight the need to know more about the antecedents of perceiving control over disease.