44 inferior meatal antrostomies in 32 patients have been followed over a period of 2 years. Control of the results by means of sinuscopy, ultrasonography, x-ray's, biopsies and subjective as well as objective findings revealed good results in 89% of the patients. Closure of the fenestration occurred in 29,5% but had no bearing on the recurrency rate of sinusitis. Improvement was noticeable even after closure. Allergy did not play an important role. Mucociliary transport was evident through the window, permitting adequate ventilation and drainage.