Background: Scleritis and episcleritis may extend to adjacent ocular tissues with blinding consequences and may be associated with potentially lethal systemic disorders. Aim: To evaluate the ocular complications and systemic disease associations of the different types of scleritis and episcleritis. Patients and methods: Forty six patients with refractory scleritis and episcleritis were studied and treated during the period 1991 to 1998. Results: Necrotizing type was the most common and severe category in the scleritis group of patients. A decrease in vision occurred in 58.3% of patients with scleritis v/s a 23.5% of patients with epiescleritis (p<0,05). Uveitis was present in 35.4% of patients with scleritis and scleromalacia was present in 33.3% (p<0,05). A specific disease association was uncovered in 51% of scleritis and in 38% of episcleritis patients. Rheumatoid arthritis, primary systemic vasculitic disease and Sjögren syndrome with vasculitis were the most common associated systemic diseases. Three patients with scleritis had tuberculosis. Conclusions: Scleritis is more severe than episcleritis, and necrotizing scleritis is the most severe type of scleritis. Classification of scleritis and episcleritis provides valuable prognostic information. A meticulous approach for the detection of a specific associated disease must be undertaken. Scleritis associated with vasculitis has a worse ocular prognosis than other non infectious diseases. Cyclophosphamide is the most effective inmunosuppresive treatment to control severe ocular involvement (Rev Méd Chile 2000; 128: 1205-14)