The course of cystic fibrosis (CF) progression in children is affected by parent adherence to treatment plans. The Theory of Reasoned Action (TRA) posits that intentions are the best behavioral predictors and that intentions reasonably follow from beliefs (“determinants”). Determinants are affected by multiple “background factors,” including spirituality. This study's purpose was to understand whether two parental adherence determinants (attitude towards treatment and self-efficacy) were associated with spirituality (religious coping and sanctification of the body). We hypothesized that parents' attitudes toward treatment adherence are associated with these spiritual constructs. A convenience sample of parents of children with CF aged 3–12 years (n = 28) participated by completing surveys of adherence and spirituality during a regular outpatient clinic visit. Type and degree of religious coping was examined using principal component analysis. Adherence measures were compared based on religious coping styles and sanctification of the body using unpaired t-tests. Collaborative religious coping was associated with higher self-efficacy for completing airway clearance (M = 1070.8; SD = 35.8; P = 0.012), for completing aerosolized medication administration (M = 1077.1; SD = 37.4; P = 0.018), and for attitude towards treatment utility (M = 38.8; SD = 2.36; P = 0.038). Parents who attributed sacred qualities to their child's body (e.g., “blessed” or “miraculous”) had higher mean scores for self-efficacy (airway clearance, M = 1058.6; SD = 37.7; P = 0.023; aerosols M = 1070.8; SD = 41.6; P = 0.020). Parents for whom God was manifested in their child's body (e.g., “My child's body is created in God's image”) had higher mean scores for self-efficacy for airway clearance (M = 1056.4; SD = 59.0; P = 0.039), aerosolized medications (M = 1068.8; SD = 42.6; P = 0.033) and treatment utility (M = 38.8; SD = 2.4; P = 0.025). Spiritual constructs show promising significance and are currently undervalued in chronic disease management. Pediatr Pulmonol. 2012; 47:558–566. © 2011 Wiley Periodicals, Inc.