The population-based Childhood Cancer Registry of Piedmont (CCRP) has collected data on incidence since 1967. The occurrence of early death (i.e. within 30 days of diagnosis) was investigated in 3006 cases of childhood cancer diagnosed during the period 1967-1998. The proportion of early deaths (178 of the 3006 cases) was analysed by period of diagnosis (three decennial periods), age group, major diagnostic group and hospital category, with univariate statistics and logistic regression. The proportion of children with cancer who died within 1 month of diagnosis was 10.8%, 5.3% and 1.8% for cases diagnosed during 1967-1978, 1979-1988 and 1989-1998, respectively. This trend may reflect earlier diagnosis, improved diagnosis, more effective therapy or more frequent referral to specialised centres. The risk factors for early death were: age <1 year and diffuse disease at diagnosis, diagnosis during 1967-1978, a diagnosis of acute non lymphocytic leukaemia, non-Hodgkin lymphoma, central nervous system tumour or hepatic tumour. Early death was not related to the sex of the child. Care in an extra-regional specialised centre was associated with lower risk of early death. CONCLUSION:no temporal changes in early mortality were found among children with acute non lymphocytic leukaemia diagnosed in the first, second or third decade of activity of the CCRP, the percentages of children dying within 1 month being 12.8%, 10.7% and 12.8%, respectively. This pattern clearly differed from the corresponding trend for acute lymphoid leukaemia (6.4%, 2.0%, 0.4%).