In terms of an assessment of incidence of late neurological complications, 178 patients (92 boys) cured from pediatric acute lymphoblastic leukemia (ALL) were examined. Children were 1 to 16 (median 11) years old at diagnosis, and 5.5 to 28.4 (median 11) years old at evaluation. Time from completion of treatment to evaluation was 0-19 (median 3) years. Abnormalities in neurological examination were found in 33 (18%) including abnormalities of: lower motor neuron in 16 (9%), pyramidal system in 6 (3%), cerebellum in 1 (0.6%), epilepsy in 8 (5%), encephalopathy in 5 (3%). Among 257 patients treated in our department for ALL (treatment started from May 1976 to December 1997), in whom treatment was completed from March 1979 to December 2000, brain tumor was diagnosed in 5 (2%). Patients should undergo periodical neurological evaluation after completion of treatment for leukemia.