From 1975 to 1986, 75 neonates were treated at the Institute Gustave-Roussy for a malignant solid tumor, comprising 1.7% of the overall oncopediatric population treated during the same period of time. Of these 75 patients, 47 (62%) presented with neuroblastomas, 15 (20%) with mesenchymal tumors, 9 (12%) with germ cell tumors and 4 with various other types of tumors. Treatment consisted of surgery in 63 patients, chemotherapy in 43 and radiotherapy in 18. The 5 year crude survival rate was 77%. Neuroblastomas did the best with a crude survival rate of 89%. The young age of the patients resulted in two types of problems: immediate tolerance and long term sequelae. The therapeutic regimen should take into account the good prognosis of the majority of these tumors in order to decrease delayed effects.