Voice therapy with the aim of raising a client's fundamental frequency is a common practice in the reassignment of male-to-female transsexuals. In female-to-male transsexuals on the other hand voice therapy is usually not considered since the administration of androgens is assumed automatically to change the voice in the direction of the desired sex. The present study examined whether the voice change in female-to-male transsexuals is indeed as straightforward as it is assumed. Results from a sample survey involving 16 female-to-male transsexuals and longitudinal data from two clients suggest that the voice change in female-to-male transsexuals is not always totally unproblematic. A voice assessment and some counselling before the hormone therapy are recommended.