Background: Health anxiety is common, impairing, and costly. The role of catastrophizing of bodily sensations (i.e. rumination about, overconcern with, and intolerance of bodily sensations) in maintaining health-related anxiety (i.e. anxiety about perceived health problems) is important, but understudied, in the health anxiety literature. Aims: The present study investigates the role of catastrophizing of bodily sensations as a maintenance factor for health-related anxiety over time. Method: Undergraduates (n = 226 women; n = 226 men) completed a baseline assessment, 14-day daily diary study, and 14-day longitudinal follow-up. Results: Path analysis indicated catastrophizing of bodily sensations maintains health-related anxiety from one month to the next in both men and women. Conclusions: The present study bridges an important gap between theory and evidence. Results support cognitive behavioral theories and extend cross-sectional research asserting catastrophizing of bodily sensations maintains health-related anxiety over time. A cyclical, self-perpetuating pattern was observed in the present study wherein catastrophizing of bodily sensations and health-related anxiety contribute to one another over time. Results also suggest targeting catastrophizing of bodily sensations may reduce health-related anxiety.