BACKGROUND Phonosurgery became an accepted surgical modality in the 1960s and refers to any surgery designed primarily for the improvement or restoration of voice. In a wider sense it also includes procedures involving the articulatory organs aiming at improvement of speech. Phonosurgery as "esthetic surgery" of the vocal organ differs clearly in its intentions from traditional laryngeal surgery which is performed because of vital indications. It is therefore necessary to define basic principles for the indication of phonosurgery. In this paper, general suggestions for the preconditions and importance of diagnostic criteria for the indication are given. 1. Diagnosis and documentation, 2. Patient's requests and needs, 3. Conservative therapeutic procedures or concept. 1. Audible findings, 2. Visible functional findings (stroboscopy), 3. Visible morphological findings. Phonosurgical interventions never should simply focus on the appearance of the vocal folds but on improving the patient's voice adapted to his or her individual requests and needs.