In a controlled study 24 patients with neurotic and psychosomatic symptoms were treated with Respiratory Feedback (RFB) in 12 consecutive sessions. The observed changes were compared with the results of a control group. Its members were subjected to a nonsystematic treatment causing them to relax (placebo-group). In this group the physical symptoms of three quarters of the patients changed for the worse whereas significant psychic changes were not observed. In the RFB-group, however, significant improvements were to be found in regard to the physical as well as the psychic condition of the patients. The most distictive changes were reduction in the disposition to exhaustion, a decrease of the vegetative symptoms, and a decline of the compleints about heart trouble, poor circulation and pains in parts of the stomach and intestinal system. Psychologically a distinct reduction of fear, neuroticism, increased extraversion scores and a positive change of mood followed. It is being discussed if the observed changes in the RFB-group can be attributed to specific effects of the Respiratory-Feedback (RFB).