This study of 220 wives of participants from four of the 22 clinics in the Multiple Risk Factor Intervention Trial (MRFIT) addresses the question of whether spouses of men exposed to a continuous coronary heart disease (CHD) risk-factor intervention program (SI group) make changes in their own risk status compared to wives of men who did not receive the intervention program (UC group). Total serum cholesterol and low-density lipoprotein (LDL) cholesterol were significantly lower for the SI wives. These differences were found for both hypertensive and normotensive wives, although the magnitudes were much greater for the hypertensive wives. There were also significant differences between the two groups of wives in the food-record rating and in dietary-knowledge scores, indicating that the probable mechanism for the beneficial effect of the intervention with respect to cholesterol levels was the change in the family diet. Although not statistically significant, differences indicating a lower risk for SI wives were found for diastolic blood pressure. There was also a greater mean reduction in cigarettes per day for SI wives who smoked.