Lipolytic response to conditions producing alterations in carbohydrate metabolism was tested on human newborn subcutaneous adipose tissue in vitro. Glycerol release from intact adipose tissue fragments or n isolated adipose tissue cells was used to indicate the rate of lipolysis. The addition of glucose increased glycerol release in isolated cells (p < 0.01–0.025) and in intact tissue fragments (p < 0.0005–0.0025) from subcutaneous adipose tissue in neonates, but did not affect the glycerol release in the same tissue in adults. Lipolysis was also significantly increased after addition of pyruvate (p < 0.025). Oligomycin and reduced oxygen tension diminished the stimulatory effect of glucose on lipolysis. Basal glycerol release was often elevated in newborns in whom the adipose tissue glycogen content was higher than in normal newborn infants of the same age.