Objectives: The purpose of this paper is to describe the demographic and clinical characteristics of chiropractic patients and to document chiropractic visit rates in 6 sites in the United States and Canada.Methods: Random samples of chiropractors from 5 US sites and 1 Canadian site were selected. A record abstraction system was developed to obtain demographic and clinical data from office charts.Results: Of the 185 eligible chiropractors sampled, 131 (71%) participated. Sixty-eight percent of the selected charts showed that care was sought for low back pain, while 32% recorded care for other reasons. Spinal manipulative therapy was recorded in 83% of all charts. There was a greater than 2-fold difference in the median number of visits related to low back pain per episode of care across sites. The chiropractic visit rates in the US sites and Ontario are estimated to be 101.2 and 140.9 visits per 100 person-years, respectively.Conclusions: The chiropractic use rate in these sites is twice that of estimates made 15 years ago. The great majority of patients receive care for musculoskeletal conditions of the back and neck. The number of visits per episode varies appreciably by site.