The research tested a model of treatment decision making in chronic illness that includes health beliefs, quality of life, and relationship with the physician (shared or not). Inflammatory bowel disease patients (N = 218) reported on their physician-patient relationship, general and disease-specific quality of life, and intentions to take a drug, for which perceived benefits and costs were manipulated. For more symptomatic patients, both costs and benefits predicted intentions; however, for less symptomatic patients, costs played a more important role. Physician recommendation predicted intention primarily among those who shared a decision-making relationship with their physician. Overall, the model accounted for 57.8% of the variance in medication-taking intention. Findings suggest that an integrative consideration of relationship factors, health beliefs, and health status may help explain treatment intentions among the chronically ill.