Between January 1984 and March 1989 twenty-seven low birth weight infants (mean birth weight 1351 gm, mean gestational age 30 weeks) required shunts after development of a posthaemorrhagic hydrocephalus. Revision of the shunt occurred in 78% of the patients with a range of 1 to 11 revisions. Obstruction of the ventricular catheter was the main cause of mechanical complications that occurred in 75%. Preterm infants weighing less than 1000 gm revealed an enormous infection rate of 71%. Initial shunt placement in the first 8 weeks of life was more likely to need shunt revision (94%) than that placed at older age (44%). There was no difference between the type of shunt and percentage of shunt revision, but the Heyer-Schulte system in comparison with the Codman Uni shunt was more likely to have mechanical complications. Infants with Grade IV haemorrhage required the same percentage of revisions as those with Grade III haemorrhage. There was no association between preoperative therapy and the need for shunt revision. A great amount of erythrocytes and very low glucose levels in the preoperative CSF were more likely to predict shunt revision than predicted by the CSF protein.