The role of surgery in the management of Stage IV neuroblastoma is still far from clear. Seventy-nine patients with this diagnosis presented to the Children's Hospital of Philadelphia during the 10-year period, 1977 to 1986. Four-year survival was 23%. A major resection of the primary tumor was undertaken in 54 patients. The timing of the procedure (at presentation or delayed) had no effect on survival. The patients were divided into three groups based on the extent of surgical resection: Group 1, no surgery or biopsy only (25); Group 2, complete gross resection (34); Group 3, incomplete resection with residual gross disease (20). Four-year survival was 16, 15, and 45%, respectively. The patients were then classified as favorable or unfavorable, on the basis of biological prognostic factors at presentation. When this analysis was combined with the extent of surgery it was discovered that Group 3 contained a higher proportion of favorable patients, accounting for the better survival. Within each group survival correlated with the expected prognosis. The outcome for a patient with Stage IV neuroblastoma depends on the biological characteristics of the tumor, and there is currently no evidence that these can be favorably altered by the timing or extent of surgical resection. Defining the appropriate role of surgery in the management of these patients will require a prospective randomized study which takes into account the inherent biological variability of the disease.