Congenital absence of the pancreas is an extremely rare condition. We participated in the care of a patient with an unusual presentation of neonatal diabetes attributable to agenesis of the pancreas. Additional clinical features of the patient included cardiac septal defects, gall bladder agenesis and duodenal malrotation. Appropriate institution of insulin, exocrine pancreatic supplements and surgical repair of the cardiac and intestinal anomalies resulted in the infant's survival. Of the reported cases of congenital pancreas agenesis, two cases have been ascribed to mutations in the insulin promoter factor-1 (Ipf-1) gene. Deletion of the Ipf-1-homolog pdx-1 in mice results in the failure of pancreas to develop. Analysis of both exons of the Ipf-1 coding sequence from the presented patient's genomic DNA, however, did not identify a mutation. These results suggest that a congenital or genetic perturbation occurred in this infant most likely before the appearance of dorsal pancreatic bud in the 3 mm long embryonic stage, around the embryonic day 25 in human development, before the onset of Ipf-1 expression. © Blackwell Munksgaard, 2005.