Background: Since 2002 in France, studies have highlighted instances of denial of care affecting beneficiaries of Universal Health Coverage (CMU) or State Medical Aid (AME). However, none have investigated this issue among homeless families. Objectives: The objective was to estimate the prevalence of denial of care due to CMU or AME as reported by women in homeless families living in the Île-de-France region, and to identify the associated factors. Materials and Methods: The ENFAMS survey, conducted in 2013 by the Observatoire du Samusocial de Paris, was carried out among a sample of 801 homeless families housed in the Île-de-France region. Their sociodemographic characteristics, housing conditions, residential mobility, and health status were collected by interviewers in 17 languages. A log-binomial regression was used to study the factors associated with refusal of care. Results: The reported prevalence of refusal of care due to CMU or AME among the 561 women in the sample covered by these health insurance plans was 22.1% (95% CI: [18.0–26.3]). Factors associated with a higher frequency of care refusal included being born abroad, having a perceived poor health status, and reporting having been treated less well by medical staff than other patients. Conclusion: This first study on the denial of care related to CMU and AME among homeless women confirms practices that violate the law, which constitute real barriers to access to care for individuals whose health status requires priority medical attention.