All cases of surgery in the neonatal period at The Children's Hospital during 1972 through 1980 were reviewed and classified; 1361 newborn infants came to surgery for 1696 procedures. During the years studied there was an almost fourfold increase in both procedures and patients. The most marked increase was in ligation of the ductus arteriosus in premature infants, which was not accompanied by an increase in surgery for necrotizing enterocolitis. Procedures for central alimentation rose markedly, usually for infants having had extensive abdominal surgery. Intestinal obstruction, omphalocele or gastroschisis, and cardiovascular anomalies increased, and shunting procedures for hydrocephalus rose faster than the incidence of myelomeningocele. Partial explanations for the changes in numbers and patterns may be found in an increasing local population, increase in the number and level of complexity of nursery beds, increasing neonatal survival, regionalization and transport patterns, and changes in medical management.