BackgroundThe purpose of our study was to determine the prevalence of traditional, complementary and alternative medicine (TCAM) use in patients with chronic diseases in lower Mekong countries.MethodsA cross-sectional study was conducted in a health care setting using a random sample of 4799 adult patients (Mean age: 52.3 years, SD = 22.7) with chronic diseases in Cambodia, Vietnam and Thailand. The measure included the International Questionnaire to measure usage of complementary and alternative medicine (I-CAM).ResultsThe 1 year prevalence of consulting TCAM providers was 26.0 %; 27.0 % in Cambodia, 26.3 % in Thailand, 23.9 % in Vietnam. The most commonly consulted TCAM providers were the herbalist (17.3 %), massage therapist (6.0 %), and acupuncturist (5.5 %). For all different types of TCAM providers more than 80 % of participants perceived the consultation as very or somewhat helpful. The own use of herbal medicine was 41.0 %, own use of vitamins 26.5 % and the own use of other supplements 9.7 % in the past 12 months. The most common self-help practices in the past 12 months included praying for your own health (30.1 %), meditation (13.9 %) and relaxation techniques (9.9 %). In multivariate logistic regression analyses, older age, rural residence and having two or more chronic conditions was associated with the use a TCAM provider; being female, urban residence, residing in Vietnam and having two or more chronic conditions was associated with the use of TCAM products; and being female, older age, rural residence, higher formal education, and residing in Cambodia was associated with the use of TCAM self-help practices.ConclusionsTCAM use is common among chronic disease patients in lower Mekong countries and is associated with several sociodemographic and disease specific factors.