In order to minimize the risk of diabetes complications, effective therapy for people with Type 2 diabetes involves lifestyle changes and poly-pharmacy targeting levels of blood glucose, blood pressure and blood fat. However, the strict targets set in recent guidelines are seldom achieved by the majority of people with diabetes. Barriers to effective diabetes therapy have been identified within the organization of health care and in the interaction between health-care providers and people with diabetes. However, health outcomes are also influenced by the culture of a society, a person's values, beliefs and attitudes, and by their family and friends. In this article, Torsten Lauritzen and Vibeke Zoffmann highlight examples of the psychological barriers to effective therapy in people with Type 2 diabetes.