Disturbances in glucose metabolism are of importance for violent behaviour in men, but studies in women are lacking. We used the 5 h-oral glucose tolerance test (OGTT) in this study of 17 female psychiatric patients, selected for violent behaviour directed against themselves (deliberate self-harm) and 17 healthy controls matched for age and BMI. Following OGTT, patients had higher glucose levels at 30 min (p = 0.007) and increased glucagon area under the curve (p = 0.011). Since a co-morbid eating disorder might affect results, we as a post-hoc analysis subgrouped the patients and found that the increased glucagon levels only were present in patients with an eating disorder. In contrast, those without an eating disorder showed a significantly lower p-glucose nadir (p = 0.015) and unaltered glucagon levels compared to controls. There were no significant differences in insulin and C-peptide levels between patients and controls. We conclude that deliberate self-harm in women may be associated with alterations in carbohydrate metabolism in certain groups. Eating disorder is a confounding factor.