The aim of this report is to describe the long-term hearing prognosis of the transmastoid trans-superior semicircular canal approach. Three patients with small petrous bone cholesteatoma of the supralabyrinthine type removed by partial removal of the superior semicircular canal (SSCC) were followed up for 13, 9, and 10 years, respectively. All patients showed good bone conduction hearing during the follow-up period without postoperative complications, including longstanding disequilibrium causing a reduction in the quality of life. As an approach to petrous bone cholesteatoma of supralabyrinthine type that occupies a small area medial to the SSCC, the transmastoid trans-superior semicircular canal approach is less invasive and is considered to be a recommended approach.