We report two young girls, the first almost 18 years old and the second 12 1/2 years old, affected with nonspecific interstitial pneumonia, both diagnosed at the age of 11 by open lung biopsy and both being treated with low-dose steroid. Due to insufficient response to conventional therapy and based on positive therapeutic results following the use of subcutaneous recombinant interferon gamma-1b in fibrosing interstitial pneumonias of adults, they were given a 1-year trial of subcutaneous recombinant interferon gamma-lb in association with a steroid. Our experience with these two young patients suggests that interferon gamma-lb cannot be considered as stabilizing or a curative therapy to control or reverse nonspecific interstitial pneumonia unresponsive to steroids alone.