Positive health behaviors are crucial to cancer survivors’ well-being, yet little is known about the personal factors that may facilitate positive health behaviors. The current study focuses on the association of religion/spirituality (R/S) and health behaviors, examining links between health behaviors and religious attendance, daily spiritual experiences, and religious struggle in a sample of 167 younger adult survivors of a variety of cancers. The extent to which positive affect (self-assurance) and negative affect (guilt/shame) mediate these links was also investigated. Results revealed that religious attendance had little impact on health behaviors, but that daily spiritual experiences were related to greater performance of health behaviors, while religious struggle was related to less. Self-assurance partially mediated the effects of daily spiritual experiences, while guilt/shame partially mediated the effects of religious struggle. The findings suggest that aspects of R/S may play important and different roles in the lifestyle choices of cancer survivors.