Objectives: To assess the long-term effectiveness of stapedotomies performed on patients with otosclerosis and preoperative small air-bone gaps (ABGs). Methods: Retrospective study comparing the 10-year postoperative hearing outcomes after primary stapedotomies in patients with small (≤20 dB) and large ABGs (> 20 dB). Ninety out of 175 stapedotomies (22 and 68 in the small and large ABG groups, respectively) were monitored with long-term follow-ups. Results: Ten years after the operation, hearing measurements were similar for both groups, although a significant decline of bone conduction thresholds was evident (p = 0.007 and p < 0.001, respectively). An improvement of ≥10 dB in the postoperative ABG (clinical improvement) was achieved only in the large ABG group. Conclusions: Even though long-term hearing levels will evolve similarly in patients with ≤20 and > 20 dB preoperative ABGs, the lack of clinical improvement found in the small ABG group is not in favor of an early surgery.