By virtue of the existing laws and regulations in Spain (i.e., Law 3/2007, of 15 March, regulating the register rectification of the entry related to a person’s sex) any person of Spanish nationality, of legal age and with sufficient capacity to do so, may request the register rectification for sex change. A new aspect regarding the legal age was introduced not long ago. In this regard, the Constitutional Court of Spain in judgment 99/2019, 18 July 2019, declared unconstitutional article 1.1 of the aforementioned Law 3/2007 since it does not allow the sex change in the registry (and, consequently, the name) to minors, who, however, have sufficient maturity and live in a steady state of transsexuality. The Court states that this prohibition implies a disproportionate interference in minors right to privacy and it is contrary to the principle that guarantees them a space for the free development of his/her identity. Under the pretext of the mentioned landmark case-law we will highlight a series of controversial issues concerning sexual rights. Obviously, this question is still subject to debate and has lost none of its urgency.