Individuals who refuse vaccines are often painted as anti-science or ill-informed. However, drawing from interviews with 50 mothers who refused one or more vaccines ( n = 50), results from this study suggest that such depictions lack nuance and may detract from the ability of communication efforts to effectively address concerns. In particular, participants' explanations for vaccine refusal relied on paradoxical arguments about science and expertise. On one hand, participants defended the ideal of science but criticized existing research for failing to meet requisite standards. On the other hand, they suggested that maternal experience could supplant the ways of knowing that give rise to such claims. Collectively, these explanations reflected critical, postmodern, and feminist perspectives on science and knowledge production and can help explain the persistence of the controversy surrounding childhood vaccines in the United States.