To retrospectively analyze the clinical features and results of treatment in 56 infants with fibrosarcoma enrolled onto cooperative European protocols between 1979 and 2005 and treated with a combination of surgery and chemotherapy. We performed a retrospective case review of infants under the age of 2 years with fibrosarcoma treated between 1979 and 2005 in six European studies. Patients were staged according to the Intergroup Rhabdomyosarcoma Staging System international classification as a function of the type of initial surgery and the extent of disease and were treated with surgery and chemotherapy. Survival was calculated using the Kaplan-Meier method. Primary tumor site was the limbs in 66% of patients; median tumor diameter was more than 5 cm in 63% of patients; and postoperative staging was as follows: group I, 22%; group II, 27%; group III, 47%; and group IV, 4%. Response rate to chemotherapy was 75%, and the specific response rate to vincristine-dactinomycin was 71%. Local control was obtained in 84% of patients. At the end of follow-up, 45% of survivors had been treated by surgery alone, 6% by chemotherapy alone, 46% by surgery and chemotherapy, and 2% by surgery, chemotherapy, and radiotherapy. The 5-year overall survival (OS) rate was 89%. The 5-year OS and event-free survival rates for localized patients were 89% and 81%, respectively. Although complete resection is rarely feasible at diagnosis, conservative surgery remains the mainstay treatment for infantile fibrosarcoma. An alkylating agent-free and anthracycline-free regimen is usually effective and should be chosen as first-line chemotherapy for inoperable tumors. Overall prognosis is good, but progression or relapse, mainly local, remains possible.