In this retrospective analysis, data of 52 patients with Ewing's sarcoma or PNET with a pathological fracture in the area of the primary tumor were evaluated. All patients were treated according to the trials CESS 81, CESS 86 P, CESS 86, CESS 91 P and EICESS 92 of the German Society of Pediatric Oncology and Haematology (GPOH). At the date of evaluation (15. September 1994) all patients had completed treatment and had been under observation for at least one year following diagnosis. The median follow-up time was 28 months. 22 patients were female, 30 male. The median age was 12 years. 75% of primary tumors had a volume of > or = 100 ml. 30 patients presented with fractures in proximal, 12 in central and 10 in distal parts of the skeleton. 10 patients had primary metastases. The histological definition was Ewing's sarcoma (including atypical Ewing's sarcoma) in 43 patients, PNET in 8 and small-cell osteosarcoma in 1 patient. For local therapy the patients underwent surgery, definitive radiotherapy or a combination of both. The percentage of primary metastases in the group of the patients with pathological fractures is comparable to the whole reference group. The present analysis focuses on those patients with pathological fractures who had no metastases at diagnosis. The relapse-free survival of patients with a pathological fracture and no primary metastases is 58%, the overall survival 65%. These rates are similar to those of the reference group of protocol patients without pathological fractures at diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)