In the last few years, substantial progress has been achieved in elucidating the pathogenesis of Wegener's granulomatosis. Several genetic risk factors have been described. The structure of the granuloma and its possible function as ectopic lymphoid tissue have been defined. Furthermore, the consecutive immunopathological reactions leading to induction of PR3-antineutrophil cytoplasmic antibodies (ANCA) and the role of ANCA itself is getting clearer. However, the initial events leading to granuloma formation are still widely unknown. Concerning therapy, the significance of the so-called biological agents (TNF-alpha-blockers, Rituximab) still has to be defined.