Deflazacort is an oxazoline derivative of prednisolone with anti-inflammatory and immunosuppressive activity. Both short (4 to 6 weeks) and longer term (13 to 52 weeks) studies have shown deflazacort to be as effective as prednisone or methylprednisolone in patients with rheumatoid arthritis. The drug was at least as effective as prednisone in children with juvenile chronic arthritis. Insufficient data are available to draw firm conclusions regarding the efficacy of deflazacort as treatment for patients with severe asthma, but the drug has demonstrated some efficacy as treatment for nephrotic syndrome and other applications such as Duchenne dystrophy, systemic lupus erythematosus, uveitis and transplantation. The overall incidence of adverse events in deflazacort recipients (16.5%) is lower than that recorded in patients treated with prednisone (20.5%) or methylprednisolone (32.7%) and similar to that in betamethasone recipients (15.3%). Gastrointestinal symptoms are the most frequently reported adverse events in deflazacort recipients; other adverse events associated with the drug include metabolic and nutritional disorders, central and peripheral nervous system disturbances and psychiatric disorders. In general, deflazacort appears to have less effect than prednisone on parameters which may be associated with the development of corticosteroid-induced osteoporosis. Further, the drug appears have less negative impact on growth rate in children with diseases requiring corticosteroid therapy. In a study of 2 months' duration in patients with conditions requiring corticosteroid treatment, moderate dosages of deflazacort produced no clinically relevant diabetogenic effects. Thus, deflazacort may be associated with less serious metabolic sequelae than prednisone but further well designed long term trials are required to confirm this. In the meantime, in adults, deflazacort should be reserved for use in those pre-disposed to, or who develop, intolerable metabolic sequelae during treatment with corticosteroids. In children, however, even though available efficacy data are minimal, deflazacort should be considered as an initial option in those requiring corticosteroid therapy since the adverse effects caused by this drug class are particularly debilitating in this patient group.