We report the experience with and evaluation of treatment strategies in fibrosing alveolitis and desquamative interstitial pneumonitis (FA/DIP) over the last 16 years by a review of all cases referred to a tertiary referral center. There were 25 cases, 16 boys and 9 girls (mean age at onset, 2.3 years; range, 7 days to 11.6 years). In each case the diagnosis was confirmed by open lung biopsy at a mean age of 3.3 years (range, 7 weeks to 15.1 years). Presently features were tachypnea (19), cyanosis (15), cough (12), exertional dyspnea (7), recurrent chest infections +/- wheezing (9), and clubbing (8). Four patients recovered without antiinflammatory medication. The others received specific treatment. Of 11 patients given only prednisolone, six improved, two did not, and three died despite treatment. Of five patients receiving only chloroquine, four responded. Five patients received both prednisolone and chloroquine; one died, two responded well. There was poor progress in the remaining two. Of the 10 patients receiving chloroquine six (60%) showed a good response. A younger presentation carried a worse prognosis, but chest radiology at presentation and outcome were not interrelated. Those with mild histological changes all survived, but severe desquamation or fibrosis at biopsy was not related to outcome. In four cases there was a family history (16%). Patients with FA/DIP probably represent a disease spectrum of multiple etiology with a variable prognosis and response to treatment.