Although no differences have been found for children raised by same-sex parents as compared with opposite-sex parents, negative attitudes toward same-sex parenting persist. Nonetheless, dehumanizing attitudes on same-sex parents are currently scarcely investigated. Within the dehumanization approach, the ontologization process is the attribution of a different «ontology» to outgroup members that serves to exclude them from the realm of humanity. This study provides preliminary evidence of the ontologization process toward same-sex parents. Two hundred Italian heterosexual participants read one of four vignettes describing a stepfamily (same-sex parents vs. opposite-sex parents). After reading the vignettes, the participants rated the stepfamily on ontologization traits. Results show that the participants attribute more animal traits to samesex parent stepfamilies as compared with opposite- sex parent stepfamilies. However, the results do not support a full ontologization process.