A negative middle ear exploration for otosclerosis is disappointing for the patient and surgeon alike. Perhaps worse is finding a pathology that the team is not prepared to manage or for which surgery is contraindicated. Accordingly, this panel presentation, sponsored by the Otology and Neurotology Education Committee, will equip clinicians to successfully distinguish and manage the range of “can’t miss” diagnoses that mimic otosclerosis. Experienced panelists will be presented with clinical cases united by a chief complaint of conductive hearing loss (CHL). Cases will include acquired and congenital ossicular pathologies (e.g., malleus head fixation), third window lesions (e.g., canal dehiscence and enlarged vestibular aqueduct), occult chronic ear disease, neoplasms, pseudo-CHL, and coincident otosclerosis and another cause of CHL. Panelists will discuss, debate, and illustrate key elements of the history, physical exam, and audiometric test battery that point to specific diagnostic possibilities. They will also discuss their approaches to imaging acquisition and interpretation. Evidence-based surgical and non-surgical management strategies for CHL will be presented for each case, including a proposal for a systematic approach to middle ear exploration when the diagnosis remains ambiguous.