We investigated two types of negative and positive social control strategies, warning and encouragement, used by spouses to urge patients with type II diabetes to improve adherence to the diabetic diet. Warning refers to things a spouse may say or do to caution the patient about the consequences of eating a poor diet, and encouragement refers to things a spouse may say or do to promote healthier food choices by the patient. Our dyadic design (n = 109 couples) assessed spouses’ use of warning and encouragement (reported by spouses and by patients), as well as patients’ reports of dietary adherence. Spouses being actively involved in patients’ dietary choices was the largest category of open-ended descriptors of both warning and encouragement. Both spousal warning and encouragement were associated with patients’ adherence to the recommended diabetic diet, with warning associated with poorer adherence and encouragement associated with better adherence. Moreover, it was the spouses’ perceptions of their own influence attempts, and not patients’ reports, that were consequential for patients’ adherence. Patients’ dietary behavior, and ultimately disease management, appears to be best served when the spouse uses more positively toned and less coercive influence attempts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)