OBJECTIVE: To identify the incidence of intra- and postoperative complications of adult and paediatric cochlear implants (CIs) in a large cohort with long follow-up. METHODS: Retrospective chart analysis of 2000 consecutive cases of CI in a single institution. RESULTS: 8.9% of paediatric CIs developed a complication after a mean period of 5.5 ± 5.8 years. 12% of adult CIs developed a complication after a mean period of 3.5 ± 5.3 years. UNLABELLED: Seroma was the most frequent paediatric complication (1.8%), after a mean of 8.9 ± 5.4 years, while vertigo was the most common complaint in adults (2.5%), emerging in the first year. Both complications were generally managed conservatively. Acute otitis media or abscess with extrusion of the receiver/stimulator required surgical revision, with or without CI explantation, in 23.5% and 76.9% of cases, respectively. Cholesteatoma or chronic otitis media were always treated surgically and required CI explantation in 86.7% of cases. All cases complicated by device failure (1.2% and 0.8% of paediatric and adult CIs, respectively) were treated with CI explantation and reimplantation, and emerged after a mean of 5 ± 4 years. CONCLUSIONS: Knowledge and decades long monitoring of the complications related to CIs are fundamental.