About 200 patients are considered each year for cochlear implant recipiency. Only 1/4 of these candidates actually receive an implant. The aim of the study is to discuss the preoperative procedure we use, which is aimed to exclude patients who would not benefit from an implant. A cochlear implant is an example of very expensive high-profile medical therapy, a single implant costing about 280,000 Austrian schillings. The aim of the preoperative diagnostic procedure is to select the right patients, with a view to providing the best audiologic outcome. During the past 20 years, important parameters have been identified to determine suitable patients. Candidates for a cochlear implant are infants and children (independent of the etiology of deafness or high-grade hearing loss), as well as postlingual deaf adults. Congenitally deaf adults or teenagers are considered unsuitable to receive an implant.