Daily life motor skills of children with acute lymphoblastic leukemia (ALL) were studied during treatment using the Movement Assessment Battery for Children (Movement ABC). In addition, the possible relation with vincristine treatment was investigated. Seventeen children treated for ALL, aged 4-12 years, were compared to an age- and sex-matched control group. The leukemia group performed more poorly than the control group on both fine and gross motor skills. In looking at the number of children with ALL who scored in the clinical range of the different subtests, problems in balance skills were found to be most pronounced at the end of induction therapy. Remarkably, half a year after reinduction therapy, problems with balance had decreased, whereas the number of children with fine motor problems had increased. A relation between the gross motor problems and vincristine neurotoxicity seems plausible based on a descriptive analysis of the data, but this was not supported statistically.