Cochlear implant has become a common treatment for people with severe hearing loss. As the field of cochlear implants is developing rapidly a larger group of patients will be implanted. Therefore, it can be of interest to identify which complications are most frequently occurring. Objective: The aim of this study is to identify and present the most common complications in cochlear implant treatment and to identify surgical issues that have to be addressed during implantation. Method: A review of retrospective case studies regarding complications has been made.