In immunosuppressed patients with clinical and radiological signs for a sinusitis and a periorbital inflammation an invasive fungal sinusitis should be considered. Pathogenic aspergillus species are the most common identified in fungal sinusitis. The disease with often lethal outcome requires a careful and fast diagnostic and therapy as well as interdisciplinary co-operation. If and when limited or extensive surgery should be performed remains, because of the rarity and the lacking experience with this disease, still a controversially discussed issue and depends on several factors: the kind of disease, the immunity, the subtype of invasive fungal sinusitis and the degree of tissue invasion.