To determine frequency, perceived effectiveness, and cost of religious, physical, and other nonmedical practices, we interviewed all (n = 402; 100% participation) of our cystic fibrosis patients/families [age, 0-45 (median, 18) years]. At least one type of nonmedical therapy was used by/on 264 (66%), two-thirds of which was religious. Most respondents perceived benefit (e.g., group prayer, 95%; religious articles, 81%; chiropractic, 69%). Only 17 (4.2%) invested over $200 lifetime (minimal compared with medical costs). These treatments, apparently used by most patients/families, rarely interfered with medical care. Physician openness and empathy toward patients' beliefs might enhance rapport and facilitate discussion of possible helpful or adverse effects of nonmedical treatment.