Abstract In Brazil, two recent laws stand out in the fight against gender violence: Law no. 11.340 / 2006, named “Maria da Penha Law”, and, more recently, Law no. 13.104 / 2015, which typifies femicide, the murder of a woman due to her gender condition. The purpose of this article is to analyze the effects of Law no. 13.104 / 2015 in the rates of violence against women, especially in the number of femicides. The number of deaths of women in Brazil in the period between 1996 and 2017 was surveyed, in order to evaluate, in a quantitative way, the effects of the new law on the numbers of gender violence, through a comparison on the temporal evolution of the indexes. The results point to an immediate decrease in the number of femicides, with a subsequent resumption of growth, indicating that there was no significant impact on these indexes. The importance of crime classification, however, goes beyond its effects on the number of deaths of women.