The van, emblazoned with the photos under a banner in both English and Spanish that says "no abortion," has been spotted numerous times on the streets of Madrid, The Local.sp reported Saturday.
The group that operates the van was formed in the United States but has recently expanded to Europe.
Jorge Benito, spokesman for Spain's Center for Bioethics Reform, the group responsible for the van protest, said it is meant to remind people of the "massacre" abortion presents to the world.
"Like with the Holocaust or with slavery, people still deny the evidence and say nonsense such as 'unborn babies have no human rights but that abortion is a right,'" Benito said.
The protest comes as Spain's conservative government considers rolling back some abortion rights reforms enacted in 2010 by the Socialist government.
Abortion was legalized up to the 14th weeks of pregnancy, or the 22nd week if a woman's health is at stake or the fetus shows serious deformities. The law as it stands brings Spain in line with most of its Eurozone neighbors.
The laws were decried by the Catholic Church in Spain and by social conservatives.
Justice Minister Alberto Ruiz-Gallardo, who's been tasked with addressing abortion reform, hasn't said what he plans to change but has said publicly women should not be allowed to abort a fetus simply because it has a deformity.