Background: A causal model developed by Koenig suggests that higher levels of spirituality and religiosity effect intermediary variables and eventually result in better mental health, which then positively affects physical function. Purpose/Methods: Using structural equation modeling, we tested the model and expanded versions that use self-report data of patients with HIV (n∈=∈345). Results: All models demonstrated good overall fit with significant parameters. The final model found that increased spirituality/religiosity predicted increased religious coping, which influenced social support. Social support, in turn, positively influenced depressed mood (as a measure of mental health); depressed mood affected fatigue; and both variables predicted self-reported physical function. These three variables predicted health rating/utility for one's health state. Additional analyses found that two covariates, religiosity and race, differentially predicted spirituality/religiosity and religious coping. Conclusion: In patients with HIV, an expanded version of Koenig's model found that increased spirituality/ religiosity is positively associated with self-reported outcomes. © 2010 US Government.