Prayer is central to religious/spiritual life, and there are many claims for its effectiveness. However, few studies have examined whether frequency of prayer predicts survival in people with a chronic illness. This study follows a nationwide United States sample of people with a chronic illness (N = 1931) from 2014 to 2020. Those who prayed on a daily basis or more were significantly more likely to survive over 6 years (Hazard Ratio = 1.48; 95% Confidence Intervals: 1.08–2.03) compared with those who prayed less often, after controlling for biomedical variables (age, medical symptoms), sociodemographics (sex, race, and education), psychosocial variables (depression, social support), and health behaviors (alcohol use, smoking, exercise, and body mass index/weight).