Protesters carried banners reading "We don't want to carry on counting victims" and chanted "We are not alone" as they brandished umbrellas in the pouring rain.
The latest victim was Adaliz Villagra, 31, assassinated Tuesday by her ex-partner in front of her children.
The government regularly publishes the number of women killed by partners or ex-partners. The number so far this year is 42, according to government statistics, with more than 1,000 killed since records started in 2003.
Earlier in June, massive protests were also staged in reaction to the "Wolf Pack" trial who were eventually found guilty of raping a young woman during the annual bull-running festival in Pamplona in 2016.
The case attracted international attention in the wake of the global #niunamas and later the #metoo movement that has highlighted sexual abuse and mistreatment of women. Spain's Supreme Court eventually ruled that the crime qualified as "rape" and not just "sexual abuse," a ruling that opened national debate about the shortfalls of the country's laws to protect victims of rape and assault.
The government of Prime Minister Pedrio Sanchez said it would press ahead with plans to change legislation related to rape after a divisive election campaign in which women’s rights and gender violence were at the heart of debate.
Spain’s new parliament has the largest share of women in any European legislature although the election saw the anti-feminist Vox party enter the assembly for the first time.