Midline Granuloma (Malignant midline reticulosis) of upper respiratory tract was known as one of the fatal diseases that involve the nasal cavity, paranasal sinuses, pharynx and larynx, with progressive localized necrotizing inflammation and granuloma formation. The disease was first described in 1897 by McBride and after Stewart many clinical and histological studies have been done in 1933. But its etiology is still unclear and therapeutic methods are still under development. The authors carried out a clinical study of 15 cases which were diagnosed and treated as midline granuloma, including 7 cases which received combination radiation and steroid therapy from January 1964 to December 1980. The results are as follows: 1) Age and Sex distribution: 6 cases fell into the ages from 30 to 39 years: 13 cases (87%) were male and 2 cases (13%) were female. 2) Primary lesion sites were nasal cavity and paranasal sinuses area (8 cases; 53%), palatine tonsil (3 cases; 20%) and pharynx (2 cases; 13%) in order. 3) Common symptoms were nasal stuffiness and sore throat (6 cases; 40%), headache (5 cases; 33%), nasal discharge and facial edema (3 cases; 20%) in order. 4) Microorganisms were identified in 4 cases: staphylococcus in 2 case, pseudomonas in 1 case and streptococcus in 1 case. 5) All 7 cases who received combination radiation and steroid therapy revealed complete regression and no recurrence. 6) Among the 5 cases, who received steroid and antibiotic therapy, 2 cases died and other 3 cases improved temporarily and then developed aggravation of symptoms.