The pediatric forms of Wegener granulomatosis (WG) are rare. The clinical picture and the profile have specificities compared to those of adults. We report a case of a girl aged of four years and a half who presented initially with a clinical picture of Henoch Schönlein purpura. Physical examination revealed additionally to purpura, scabby lesions on the buttocks. The histopathological examination of a skin biopsy disclosed histiocyte infiltration. There were no Ig A deposits on direct immunofluorescence study. One year later, the diagnosis of WG was suspected, when the patient developed a respiratory problem related to left pulmonary infarction. Screening for thromboembolic factors was positive for antiphosphilipid antibodies. Diagnosis of WG was confirmed by the histopathological study lung tissue and a significant titre of serum ANCA. Blood tests failed to provide evidence of renal involvement. Cyclophosphamide and prednisolone therapy was administrated. A relapse occurred one year later on the controlateral lung; but no biological marker of disease activity could be detected.