Shoulder stiffness is associated with diabetes mellitus. It is characterized by pain and restriction of active and passive range of motion. Like other complications of diabetes (e.g., arterial stiffness, pancreatic or renal fibrosis), shoulder stiffness is due to a fibrotic process. The clinical course is generally benign, but it can last for months, with remaining disabilities in the long term. Several possibilities of treatment are being used. The practitioner should be aware of this complication, its natural history, and the current treatments available in order to adequately tailor the best treatment to the patient, sometimes combining more than one option.