Carbohyrate intolerance is a common feature of acromegaly. Frank diabetes mellitus is seen in about 10-20% of patients. There is no report of acromegaly presenting with diabetic ketoacidosis (DKA), associated with retinitis pigmentosa (RP), in the literature. We report the occurrence of DKA and RP in a patient with acromegaly. A 39-year-old Turkish man was admitted to the emergency ward with a 1-mo history of thirst, polyuria, weight loss of 10 kg, and loss of consciousness for 2 d. Physical examination revealed findings suggestive of acromegaly, including coarse facial features and enlargement of his hands and feet. At ophthalmological examination, funduscopy showed RP. Laboratory studies confirmed the diagnoses of DKA and acromegaly. Magnetic resonance imaging disclosed the presence of a pituitary adenoma. During the medical treatment with octreotide, symptomatic sinusoidal bradycardia was developed (pulse rate 45 bpm, and blood pressure 70/40 mmHg). Octreotide therapy was stopped. Pituitary adenoma was removed surgically. For treatment of DKA, insulin need was very high in the first days after the onset of ketoacidosis, but decreased after initiation of treatment with octreotide and after successful operation. insulin was stopped 7 d after surgery. Follow-up showed normalization of growth hormone levels and plasma glucose levels. Only six other cases of DKA associated with acromegaly and only three other cases of RP associated with acromegaly were found in the medical literature. In conclusion, to our knowledge, the present case is a first report of DKA an RP in patient with acromegaly.