The diagnosis of neuroblastoma in its early stage, especially in asymptomatic children, with the so-called incidentally diagnosed disease, may be associated with a good prognosis. The aim of this study is an attempt at analyzing this problem. Between 1 January 1993 and 30 April 1998, 40 children with newly diagnosed neuroblastoma started therapy at the authors' department. The disease was diagnosed incidentally in 5 (12.5%) patients. In no incidentally diagnosed child was stage IV disease detected, while in the remaining patients its incidence was 71%. All the children (median age 2 months) with incidental diagnosis have remained alive (median 39 months) in continuous remission without treatment. Among 35 children (median age 2 years and 7 months) with overt neuroblastoma, 18 died (median survival time 14.5 months). Seventeen patients have remained alive (median 45 months). The results show that children with incidentally diagnosed neuroblastoma are characterized by a more favorable prognosis than children with clinical disease.