A 69-year-old diabetic patient taking oral hypoglycemic drugs and with no systemic complications presented a right peripheral facial palsy, and 2 months later a complete right external ophthalmoplegia with sparing of the pupillary function. Clinical, radiologic, and other laboratory investigation ruled out compressive, infectious, and inflammatory etiology. Four months later, after achieving good metabolic control, there was almost complete recovery of the ophthalmoplegia without signs of aberrant regeneration of the third nerve. Diabetes is proposed as the etiology of this case. A possible anatomic substrate is presented to explain the findings.