This study established whether length of hospital stay (LOS) in Canadians 50 years and older is attributable to their vertebral fractures versus comorbid conditions. The study used a case-control design and data in the Canadian Institute for Health Information (CIHI) database on hospital discharges in Ontario, Alberta, and British Columbia between April 1, 1996 and March 31, 1997. Patients with vertebral fractures were identified by International Classification of Diseases (ICD-9) codes. LOS constituted the dependent measure in a multivariate linear regression that calculated the independent contributions to LOS by vertebral fractures while controlling for: age, gender, province, discharged deceased, hip fractures, all other fractures, motor vehicle accidents, all other injuries, and the major disorder classifications in ICD-9. Mean LOS for all patients admitted for vertebral fractures was 10.1 days. LOS attributed solely to vertebral fractures was 4.8 days based on a 50-year-old woman with no comorbid conditions, and 6.1 days based on a 75-year-old woman. Of 18 health conditions, vertebral fractures were among the top 3 in accounting for LOS, along with hip fractures and mental disorders which accounted for 5.9 days and 6.1 days in a 50-year-old woman. Among patients admitted for other problems, comorbid vertebral fractures added 2.1 days. These findings indicate that hospital stays for vertebral fractures are lengthy despite control for comorbidity.