ABSTRACT:The cranial computed tomograms (CT) of 36 asymptomatic children with acute lymphobiastic leukaemia (ALL) were obtained after 3 years continuous complete remission (CCR). In all these children central nervous system (CNS) in volvement had been excluded at initial assessment. All were regularly followed to monitor haematologic as well as CNS remission.Our study revealed that 22 of the 36 cases showed one or more of the following changes on brain CT: subarachnoid space widening, ventricular dilatation and intracerebral hypodense areas.Significantly, intracerebral calcification was absent. In 2 cases, however, the pineal was calcified and regarded as a variant of normal. Changes on brain CT were documented as severe if more than one of the three criteria mentioned existed (6 cases). Serial cranial CT scans were available in 3 children, one of whom showed regression of a hypodense periventricular lesion.Although CNS prophylaxis has dramatically increased survival time in childhood ALL, our findings concur with those of Peylan‐Ramuet al1that treatment‐induced structural changes detectable on CT do occur in a considerable pro portion of asymptomatic disease‐free children in long‐term re