In Canada, CNS tumors accounted for nearly 22% of the new childhood cancer diagnoses during 1995-2000 in the ≤ 15 year age group. The study's objective was to describe children and youth (age <20 years) diagnosed with CNS tumors in Alberta, Canada during a 22-year period using population-based data. The Alberta Cancer registry was used to extract information, including sex, age and geography, on all CNS (ICCC-3 III) tumor diagnoses during April 1, 1982, and March 31, 2004. Analyses included population summaries and rates. During 22 fiscal years, 568 Alberta children were diagnosed with CNS tumors and nearly 82% of the cases were malignant (461). The majority of cases were male (322, 57%) and the median age at diagnosis was 8 years. The crude rate per 100,000 children increased over the study period from 2.1 in 1983/1984 to 4.2 in 2003/2004. Astrocytoma was the most common diagnosis (257, 45%), followed by medulloblastoma (12%), mixed and unspecified glioma (9%) and ependymoma (9%). There were 86 diagnoses of juvenile pilocytic astrocytoma (55% male) and the crude rates per 100,000 increased during the study (<0.5 in the early years to 1.15 in 2003/2004). Our data suggests an emerging trend with the latter few years having a seemingly higher standardized incidence rate than earlier years. Further study is required to determine if the trend persists.