Direct delivery of medication to the sinuses with standard nebulizers is difficult to achieve. The nasal inhalation of aerosolized medications is dependent on the size of the particles and the pressure with which they are delivered; when the particles are too small or the pressure is too low, the drug cannot reach the sinuses. The ability of topical medications to treat sinus disorders can be improved if the medication could be delivered directly to the sinuses. We tested the ability of the RinoFlow nasal aerosol delivery device to deposit aerosol directly to the paranasal sinuses. Five normal, healthy subjects used the device to administer technetium Tc 99m nasally. Nuclear scanning was used to detect deposition in the frontal and maxillary sinuses. Three subjects underwent additional testing after administration of a nasal decongestant. Three of the five subjects showed some evidence of direct delivery to the sinuses, although deposition was not uniform or complete. Pretreatment with a decongestant had no apparent effect on subsequent technetium delivery. We conclude that the results of this study are promising and that further study is warranted.