Prenatal starvation in the guinea pig causes reduced pulmonary diffusing capacity and retarded alveolarization among neonates. To study the impact of such starvation on biochemical and mechanical properties of the neonatal lung, pregnant guinea pigs were fed ad libitum throughout gestation or starved with 50% rations during their last trimester. Neonatal body weight was 35% less due to starvation, and dry lung weight, DNA, and protein contents were decreased 26, 36, and 31%, respectively (P less than 0.001 for all). Hematological data indicated no anemia, hypoproteinemia, or altered glucocorticoid levels due to starvation. Total surfactant phospholipids in these neonates were reduced 61% in lavage and 35% in the neonatal lung tissue, although surfactant compositions were similar to controls. Specific lung compliance in the air-filled lungs was not altered, but the saline-filled lungs were more distensible over deflation pressures of 9-18 cmH2O (transpulmonary). Although starvation retarded both lung cellularity and surfactant, only that portion of lung elastic recoil attributable to tissue forces was affected.