In order to describe the incidence, distribution and prognosis of neonatal cancer, 76 cases (44 boys, 32 girls) of cancer in the first 28 days of life were identified in the Danish Cancer Registry within the period 1943-85. All cases were re-evaluated and the International Classification of Disease for Oncology (ICD-O) code was applied. The incidence is calculated to 2.38 (1.88-2.98) cases per 100,000 births. The most common tumour was neuroblastoma (26%) followed by leukaemias (16%), soft tissue sarcomas (14%) and brain tumours (11%). The five year survival rate was 25% (15.1-39.0) with the highest survival rate among soft tissue sarcomas (55%) and neuroblastomas (25%) and the lowest among leukaemias and brain tumours (0). Eighteen per cent of the cases were incidental findings. Two cases of secondary malignancy were identified.