This paper is a preliminary report of 50 cases of chronic maxillary sinusitis which have undergone Caldwell-Luc and de Lima operations. The pre-operative symptoms, physical signs, and pathological reports are analysed. In a later report an evaluation of post-operative recurrences and physical findings will be presented. All 50 cases had transantral ethmoidectomy (E. de Lima procedure) at the time of the Caldwell-Luc operation. Biopsies showed chronic inflammation. We intend to determine by follow up studies whether the incidence of recurrance of maxillary sinusitis is reduced by doing these two procedures concurrently.