The relationships among stress, obesity, and inflammation in women remain unclear. This study examined the relationships among marital stress, waist circumference, and C-reactive protein (CRP) in 201 healthy women from the Stockholm Female Coronary Risk Study. We tested whether marital stress was associated with CRP and whether this association was moderated by waist circumference. Hierarchical multiple regression revealed that after adjusting for age, occupation status, fasting glucose, apolipoprotein A1, apolipoprotein B, blood pressure, smoking, and menopausal status, marital stress was not directly associated with CRP. However, waist circumference significantly moderated the association between marital stress and CRP (p = 0.012) such that marital stress was significantly associated with higher CRP among women with larger waist circumferences but not in those with smaller waists. More obese women may be particularly vulnerable to the effects of marital stress by manifesting higher inflammation.