With the advent of improved therapy, many of the childhood malignant diseases have become chronic. This group of patients and their families demonstrate many problems usually not associated with the primary disease, but which can become incapacitating. School phobia was selected as one such problem for this study. The 11 cases reported here demonstrate the insidious and subtle nature of the onset of the disease. With aggressive management, some longstanding cases of school phobia could be reversed, but not all. In a group subjected to a prophylactic regime at the onset of their malignant neoplasm, there have been no new cases of school phobia. It is important for pediatricians caring for these children to search actively for the signs of school phobia and intervene as soon as possible.