The clinical value of computerized body tomography (CT) was analysed in 221 consecutive examinations performed in the evaluation and surveillance of 74 children with various types of extracranial solid malignant tumours. CT was performed as part of a routine diagnostic reassessment in 104 cases and was clinically indicated in 117. CT detected subclinical relapse in five cases in the first category of scans and was diagnostic of local recurrence, progression or complications in 20 of the clinically indicated examinations. CT has been non-contributory or incorrect in 12 cases, and informative about the therapeutic response or confirmative of remission in the remaining scans. In order to utilize the limited capacity of the scanner in the best way possible, CT should primarily be performed in patients, where clinical findings indicate need for further investigations. Its use as an adjunct in the periodic diagnostic reassessment should be restricted to high risk patients or selected cases, otherwise difficult to investigate.