This study examines the prevalence, costs, and patterns of use of unconventional therapies in the United States. It is based on a national telephone survey of 1,539 adults conducted in 1990. The study found that 34% of respondents used at least one unconventional therapy in the past year, with a third of these individuals seeing a provider for such therapy. On average, these individuals made 19 visits per year, with an average charge of $27.60 per visit. The use of unconventional therapy varied among socio-demographic groups, with higher use reported among non-black individuals aged 25-49, those with higher education and income, and those living in the West. The most commonly used unconventional therapies were relaxation techniques, chiropractic, and massage. The majority of users of unconventional therapy also sought treatment from a medical doctor, but 72% did not inform their doctor about their use of unconventional therapy. The estimated number of visits to unconventional therapy providers in 1990 was 425 million, exceeding the number of visits to all primary care physicians. Expenditures associated with unconventional therapy in 1990 amounted to approximately $13.7 billion, with three-quarters paid out of pocket. The study concludes that the use of unconventional therapy in the United States is far higher than previously reported. Medical doctors should ask about their patients' use of unconventional therapy whenever they obtain a medical history. The findings suggest that unconventional therapy is widely used for non-life-threatening conditions and that many patients do not inform their doctors about their use of such therapies. The study highlights the need for improved communication between patients and doctors regarding unconventional therapies.This study examines the prevalence, costs, and patterns of use of unconventional therapies in the United States. It is based on a national telephone survey of 1,539 adults conducted in 1990. The study found that 34% of respondents used at least one unconventional therapy in the past year, with a third of these individuals seeing a provider for such therapy. On average, these individuals made 19 visits per year, with an average charge of $27.60 per visit. The use of unconventional therapy varied among socio-demographic groups, with higher use reported among non-black individuals aged 25-49, those with higher education and income, and those living in the West. The most commonly used unconventional therapies were relaxation techniques, chiropractic, and massage. The majority of users of unconventional therapy also sought treatment from a medical doctor, but 72% did not inform their doctor about their use of unconventional therapy. The estimated number of visits to unconventional therapy providers in 1990 was 425 million, exceeding the number of visits to all primary care physicians. Expenditures associated with unconventional therapy in 1990 amounted to approximately $13.7 billion, with three-quarters paid out of pocket. The study concludes that the use of unconventional therapy in the United States is far higher than previously reported. Medical doctors should ask about their patients' use of unconventional therapy whenever they obtain a medical history. The findings suggest that unconventional therapy is widely used for non-life-threatening conditions and that many patients do not inform their doctors about their use of such therapies. The study highlights the need for improved communication between patients and doctors regarding unconventional therapies.