Since 1967, the Childhood Cancer Registry of Piedmont measures cancer incidence and lethality among children aged 0-14 residents in the Region. Two thousand seven hundred twenty cases were recorded in the period 1967-94. Males were 55.4%. The highest frequency was observed in the age class 0-4 including 41.3% of cases. The most frequent malignancies were: Acute Lymphocytic Leukemias, CNS Tumours and Lymphomas. Incidence rates showed limited variation, both for total neoplasm and for the largest diagnostic categories. On the contrary, lethality decreased markedly: rate (per million children years) was 77.2 in 1967-69 and 59.4 in 1988-94. This trend as more evident for acute leukemias and CNS tumours. Better diagnostic techniques, anticancer and support therapies are the likely explanation for the improved prognosis. Prevalence increased, as a consequence of improved survival and curability: in the Province of Torino it increased from 62 cases per 100,000 children (age 0-14) in 1980 to 98 cases in 1994.