HIV/AIDS-related stigma is a key factor impeding patient utilization of HIV testing services. To destigmatize HIV testing, the Centers for Disease Control and Prevention recommended an 'opt-out' screening strategy aimed at all patients in all clinical settings, regardless of HIV risk. This study assessed whether opt-out screening as compared to opt-in screening was associated with increased uptake of HIV testing among patients with HIV/AIDS-related stigma concerns. This study included 374 patients attending two Los Angeles ambulatory care clinics. Stigma items were grouped into three constructs: Blame/isolation, abandonment, and contagion. Individuals endorsing the blame/isolation subscale (AOR = 0.52; 95 % CI 0.29-0.92; p\0.05) and abandonment subscale (AOR = 0.27; 95 % CI 0.13-0.59; p\0.01) were significantly less likely to accept an HIV test. Additionally, the opt-out model did not counter the negative effects of stigma on HIV test acceptance. These findings indicate that stigma remains a barrier to HIV testing, regardless of the opt-out screening approach.