A population-based case-control study was conducted utilizing linked cancer registry and birth certificate data to examine potential associations between selected birth characteristics and the occurrence of brain tumors in children. Cases (n = 157) were those children ages 10 and under who were born in Washington state and who were diagnosed with a primary brain tumor between 1974 and 1986. Controls were randomly selected from the Washington State birth files and were matched 5:1 to cases on year and county of birth. A limited number of positive findings emerged from the study. Results suggested that high birthweight may be related to an increased risk of childhood brain tumor (odds ratio (OR) = 1.4, 95% CI 1.0-2.0 for all histologies combined; OR = 1.9, 95% CI 1.1-3.1 for astrocytomas). The risk of astrocytoma was also observed to be associated with older maternal age (OR = 2.2, 95% CI 1.2-4.0) and a history of prior fetal death(s) (OR = 1.9, 95% CI 1.0-3.8).