We report a 5-year follow-up of two 4-year-old boys with classical Duchenne dystrophy, with an out-of-frame deletion in the Duchenne gene and absence of dystrophin in their muscle, who had a quite remarkable response to an intermittent, low-dosage, regime of prednisolone (0.75 mg/kg/day for 10 days each month, or alternating 10 days on and 10 days off). In the first case there was complete remission of all clinical signs of dystrophy, sustained almost fully up to the present time; in the second, the initial response was almost as marked, sustained for almost 5 years, before showing a fairly rapid decline over the ensuing year that resulted in loss of independent ambulation at the age of 10. Both boys remained around the 50th centile for height and weight, and showed no evidence of demineralization of bone on consecutive dual X-ray absorptiometry scanning of the spine, nor any signs of chronic prednisolone toxicity. These carefully documented individual cases suggest there may be an optimal window for treatment in the early stages of the disease, and further larger scale controlled studies should be targeted more selectively at this stage of the disease. This report also confirms that our regime of low dosage, intermittent prednisolone, with cycles of 10 days of treatment, either per month or alternating with 10 days off treatment, is well tolerated and can therefore be recommended for long-term use in children with Duchenne muscular dystrophy.