To discuss the clinical presentation, diagnostic criterion and treatment principle of acute fulminant invasive fungal rhinosinusitis (AFFS).Six patients were diagnosed as AFFS based on history, nose, especially eye symptoms with or without fever, sinus CT and MRI, endoscopic and cytological findings in the nasal cavity. Surgical debridement was performed on 5 of 6 biopsy proven AFFS patients, one of them being amputated of the orbital content. With the original disease controlled simultaneously, 4 of 5 patients were prescribed with systemic amphotericin B or liposomal amphotericin B (1 case) and one with Itraconazole orally. One patient had not been involved with any of the anti-fungi measures.Mucor (Zygomycetes) was identified on culture in 1 patient, Rhizopus species in 2, Aspergillus in 1, Alternaria in 1 and mixed Mucor and Rhizopus in 1. All patients were proved of tissue invasion histopathologically through biopsy. One patient died without any anti-fungi therapy on the 7th admission day, 3 patients survived for 88 days, 32 and 6 months respectively and died of original diseases (diabetes 1, leukaemia 2). One patient survived 9 months and lost for follow-up, 1 patient survived 11 months after treatment.A high index of suspicion and early endoscopic investigation through nasal cavity with fungal investigation should highly be strengthened for recognition of this disease. MRI findings should be considered as, or even more, important as that of CT scan on the early diagnoses. Extensive and aggressive surgical debridement, prompt and enough dosage of antifungal therapy intravenously, together with serious controlling of the underlying disease, all take important roles in the complete control of the disease.