BACKGROUND/OBJECTIVE: Having a serious illness such as HIV/AIDS raises existential issues, which are potentially manifested as changes in religiousness and spirituality. The objective of this study was (1) to describe changes in religiousness and spirituality of people with HIV/AIDS, and (2) to determine if these changes differed by sex and race. METHODS: Three-hundred and forty-seven adults with HIV/AIDS from 4 sites were asked demographic, clinical, and religious/spiritual questions. Six religious/spiritual questions assessed personal and social domains of religiousness and spirituality. RESULTS: Eighty-eight participants (25%) reported being "more religious" and 142 (41%) reported being "more spiritual" since being diagnosed with HIV/AIDS. Approximately 1 in 4 participants also reported that they felt more alienated by a religious group since their HIV/AIDS diagnosis and approximately 1 in 10 reported changing their place of religious worship because of HIV/AIDS. A total of 174 participants (50%) believed that their religiousness/spirituality helped them live longer. Fewer Caucasians than African Americans reported becoming more spiritual since their HIV/AIDS diagnosis (37% vs 52%, respectively; P<.015), more Caucasians than African Americans felt alienated from religious communities (44% vs 21%, respectively; P<.001), and fewer Caucasians than African Americans believed that their religiousness/spirituality helped them live longer (41% vs 68% respectively; P<.001). There were no significantly different reported changes in religious and spiritual experiences by sex. CONCLUSIONS: Many participants report having become more spiritual or religious since contracting HIV/AIDS, though many have felt alienated by a religious group-some to the point of changing their place of worship. Clinicians conducting spiritual assessments should be aware that changes in religious and spiritual experiences attributed to HIV/AIDS might differ between Caucasian and African Americans.