Voice feminization is an important step in the therapy of male-to-female transsexualism. Approaches are conservative voice therapy and surgical interventions. The most powerful parameter of gender perception is the fundamental frequency. Besides the vocal pitch, there are other parameters influencing gender perception of a voice, e. g. intonation, prosody or formant frequencies. In 21 male to female transgender persons after surgical elevation of the vocal pitch the Voice Handicap Index (VHI), the Life Satisfaction Questionnaire (FLZ) and a new addendum were used. A new algorithm for voice feminization in male-to-female transsexualism was deduced. After elevation of the vocal pitch, the self-confidence of the male-to-female transgender persons has increased. Despite of an elevated pitch some persons were not satisfied with their voice. Surgical intervention changes only the pitch of a voice. To change other parameters, conservative voice therapy is necessary. If the transgender persons are able to reach a satisfying female voice with conservative voice therapy alone, surgical intervention is not indicated.