Stigma affects adversely the HIV prevention continuum and care cascade. Our population-based, mixed-methods study aimed to assess women's perceived HIV stigma and discriminatory attitudes, and their relation with HIV testing in a high-prevalence area in Belize. This population-representing household survey in the mixed urban-rural setting of Stann Creek District, Belize, collected data from 236 women age 15 to 49 years. We analyzed HIV testing rates, HIV prevention and transmission knowledge, perceived stigma manifestations, and participant attitudes. Concurrently, a nested qualitative component of study cognitive interviews with a purposive sample of 23 women explored HIV stigma in their community. A vast majority of women (96%) perceived HIV stigma manifestations in their communities as pervasive and a deterrent to people from testing. Discriminatory attitudes (16% believe children with HIV should not attend school) and HIV misconceptions (53% fear acquiring HIV through saliva) tended to be more common in nonurban areas and among women with less formal education. Stigma persisted even with high HIV testing rates among women. Qualitative findings triangulated survey results and, taken together, suggest that prejudices held against people with HIV led to avoidance of HIV preventive measures such as testing and status disclosure, fueled by a strong distrust of the medical care system regarding confidentiality of HIV test results. Misconceptions about HIV and stigmatizing attitudes remain pervasive among women in Stann Creek, Belize. Health literacy, stigma interventions, and expansion of routine confidential testing to include men are needed to address the HIV and stigma syndemic in Belize.