No cicatricial retrolental fibroplasia has occurred in any of the 148 infants who have received severely limited oxygen therapy in the Bellevue Hospital Premature Infant Nursery during the past 2½ years. We believe that retrolental fibroplasia can be either completely or almost completely eliminated by administering oxygen only at times of clinical need, and then for as brief periods as possible and at concentrations less than 40 per cent. Mortality rose slightly during the period of oxygen limitation; the rise was not statistically significant. The possibility of a relationship to oxygen limitation is discussed; the writers believe that such a relationship is not likely.