60 patients, aged 15–51 years, with chronic allergic or bacterial maxillary sinusitis, were entered in a controlled, double-blind study comparing the efficacy of endonasal irrigations of tixocortol pivalate (Pivalone® )-neomycin and neomycin. The treatment lasted 11 days and was administered once daily. A ventilometric measurement of sinus pressure was performed every two endonasal irrigations to assess treatment efficacy. The percentage of nasal deobstruction was significantly higher with tixocortol pivalate-neomycin than with neomycin alone by the fifth examination (9th day) regardless of the etiology of the sinusitis (allergic or bacterial). After 11 days of treatment, significantly better results were obtained in cases of bacterial sinusitis (94% deobstruction with tixocortol pivalate-neomycin versus 74% with neomycin) than in cases of allergic sinusitis (69% deobstruction with tixocortol pivalate-neomycin versus 36% with neomycin).