The effects of reducing stress on glucose metabolism in diabetics were evaluated in 20 patients with type 2 diabetes (10 of each sex) who were given an anxiolytic (fludiazepam) for 12 weeks. Patients were tested 4 weeks before the start of anxiolytic treatment (A), immediately before the first dose (B), and before the end of the study period (C) using the State-Trait Anxiety Index and glycosylated haemoglobin levels. There were no significant differences between the trait or state anxiety scores or the glycosylated haemoglobin levels at times A and B before treatment. However, for all three measurements, the values at time C, after treatment, showed significant improvements, compared with those at both times A and B (P < 0.05). The improvement in the trait anxiety score was weakly correlated with the decrease in the glycosylated haemoglobin level (r = 0.426, P < 0.01). No correlation was seen between state anxiety scores and glycosylated haemoglobin levels. The results suggest that suppressing anxiety in patients with type 2 diabetes reduces glycosylated haemoglobin levels.