Background: The use of complementary and alternative medicine (CAM) therapies have been reported for the management of arthritis. However, little is known about CAM use among adults with self-reported doctor-diagnosed arthritis. Objectives: To determine (1) the prevalence and type of CAM use, (2) the difference in characteristics between CAM users and non-CAM users, and (3) the factors related to CAM use, among U.S. adults with self-reported doctor-diagnosed arthritis. Design: Secondary analysis of the 2012 National Health Interview Survey (NHIS) data. Setting: The NHIS is a cross-sectional survey that gathers health-related data on the civilian, noninstitutionalized U.S. population. Participants: The NHIS 2012 uses a complex, multistage sampling design and oversamples minorities to achieve population representation; it included 34 525 adults, with 7179 adults having arthritis. Methods: Data were analyzed using Stata 15.1 survey syntax. The potential factors related to CAM use included sociodemographics and health-related characteristics. Main Outcome Measurements: CAM modalities were categorized into six groups: natural products, manipulative therapies, mind-body therapies, special diets, movement therapies, and other practitioner-based CAM modalities. Results: Of the adults with arthritis, 2428 (weighted estimate of 36.2% of U.S. adult population) had used CAM within the last year. Adults with arthritis reported greater use of CAM than those without, particularly the use of natural products, manipulative therapies and other practitioner-based CAM modalities. Factors associated with higher CAM use included being female, residing in regions other than the U.S. South, having a college degree or higher, reporting very good/excellent self-rated health status, and having current symptoms of joint stiffness/pain. Conclusion: As more than one-third of U.S. adults with arthritis seek CAM therapies, open and nonjudgmental conversations between conventional medicine providers, CAM providers, and patients should be encouraged to ensure patient health care needs are being met. Level of Evidence: III.