A case of retroperitoneal lipoma in a 23-mo old girl is reported together with a brief review of the 11 previously documented cases. It has been encountered through age 8 yr and twice as frequently in girls. The majority had an enlarged abdomen of long duration. The others were asymptomatic and found incidentally or at the time of examination for abdominal pain. Most lipomata were large. The possibility of their being congenital cannot be excluded. None have recurred.