OBJECTIVE - To describe the cross-sectional relation between glycemic control and physical symptoms, emotional well-being, and general well-being in patients with type II diabetes. RESEARCH DESIGN AND METHODS - The study population consisted of 188 patients with type II diabetes between 40 and 75 years of age. Patients were treated with blood glucose-lowering agents or had either a fasting venous plasma glucose level ≥7.8 mmol/l or an HbA(1c), level >6.1%. Multiple regression analyses were performed. Dependent variables were scores on the Type II Diabetes Symptom Checklist, the Profile of Mood States, the Affect Balance Scale, and questions regarding general well- being. The primary determinant under study was HbA(1c). In addition, age, sex, neuroticism (indicating a general tendency to complain), insulin use, and comorbidity were included as determinants in all analyses. Other potential determinants taken into consideration were hypoglycemic complaints, marital status, diabetes duration, cardiovascular history, blood pressure, BMI, waist-to-hip ratio, perceived burden of treatment, and smoking. None of these potential determinants had to be included to correct confounding of the relation between HbA(1c), and well-being scores. RESULTS - Higher HbA(1c) levels were significantly associated with higher symptom scores (total score, hyperglycemic score, and neuropathic score), with worse mood (total score, displeasure score, depression, tension, fatigue), and with worse general well-being. The relative risks varied between 1.02 and 1.36 for each percentage difference in HbA(1c). The relation between HbA(1c) and some mood states was modified by neuroticism: in the less neurotic patient (i.e., one who is less inclined to complain), the relation was more evident. CONCLUSIONS - These data suggest that better glycemic control in type II diabetes is associated with fewer physical symptoms, better mood, and better well-being, in a nonhypoglycemic HbA(1c) range.