Optimal hearing is one goal of otologic surgery. It is generally presumed that hearing thresholds after tympanoplasty-mastoidectomy surgery are determined by remaining anatomy. We assessed the effect of the disease process on hearing after surgery, and our data do not support this presumption. We studied the relationship between preoperative and postoperative hearing across tympanoplasties with differing anatomies in 124 patients without ossicular reconstruction with prostheses or bone. Our results indicate that poor hearing before surgery is associated with poor hearing after surgery, regardless of anatomy (type of tympanoplasty). This relationship holds for both the airbone gap and the speech-reception threshold. When considering ossicular reconstruction, the surgeon should remember that the disease process itself affects hearing in addition to the physical attributes of the ear. These results should be considered in preoperative counseling, as well as in the interpretation of the otologic literature.