Seven cases of fibromatoses in infancy and childhood serve as examples to demonstrate this group of rare tumours, taking especially the aggressive forms of juvenile fibromatoses into account. There is a tendency to locally invasive destructive growth without metastasising at any time and a markedly high relapse rate after surgery--a tendency that showed up clearly in our patients, too. Only one child out of four having infantile (desmoid-type) fibromatosis of different localisation did not show any recurrence. The article reports, among other cases, on a desmoid of the stomach and oesophagus in a 15-year-old girl, not described in the literature so far, and on a congenital fibromatosis of the pancreas. Several classifications had to be performed to properly grade the individual cases (1, 6), since no generally valid systematic description of these tumours exists.