Both the ownership and development of sex dolls and robots are passionately debated, with skeptics suspecting that their increasing human-likeness and the accompanying anthropomorphization (i.e., attributing human-likeness) reinforce the objectification of, and hostility toward, women. As empirical data are largely lacking, we scrutinized this hypothesis in a pre-registered study among doll owners (N = 217), comparing two user groups: "toy group" (n = 104; doll as sex toy) and "partner group" (n = 113; doll as partner). We related their objectification tendencies (i.e., seeing women merely as objects, e.g., to promote sexual desire) as well as their hostility toward women, to the anthropomorphization of their doll. Additionally, we collected qualitative data on how participants perceived their doll usage affected their attitudes toward women. The partner group expressed greater levels of hostility and anthropomorphization, moderate in magnitude. Objectification mediated the influence of anthropomorphization on hostility and a higher percentage described a change in attitudes toward women in response to doll use. These data provide the first empirical evidence that the tendency to anthropomorphize dolls is related to negative attitudes toward women. Given the ongoing development of sex robots designed to surpass dolls in human-likeness and anthropomorphization, this finding seems highly significant.