Steroids are widely used in all sub-specialties of medicine as anti-inflammatory or immunosuppressive agents. Glucocorticoid-induced diabetes mellitus is a known but poorly reported complication of steroid therapy in developing countries. We report a case of steroid-induced diabetes mellitus in a 14 year old female nephritic adolescent who developed diabetic ketoacidosis while on prednisolone therapy for nephrotic syndrome. She presented with two day history of abdominal pain, one day history of frequent loose stool and vomiting. She was restless on admission, had random blood glucose of 32mmol/L and 3+ of ketonuria. She was successfully managed with insulin therapy over a four month period while she was gradually weaned off prednisolone. Diabetes mellitus is a common life-threatening complication of steroid therapy which requires good clinical surveillance and prompt management.