BACKGROUND: Low back pain (LBP) in older adults is poorly understood because the vast majority of the LBP research has focused on the working aged population. The aim of this study was to compare older adults consulting with chronic LBP to middle aged and young adults consulting with chronic LBP, in terms of their baseline characteristics, and pain and disability outcomes over 1 year. METHODS: Data were systematically collected as part of routine care in a secondary care spine clinic. At initial presentation patients answered a self-report questionnaire and underwent a physical examination. Patients older than 65 were classified as older adults and compared to middle aged (45-65 years old) and younger adults (17-44 years old) for 10 baseline characteristics. Pain intensity and disability were collected at 6 and 12 month follow-ups and compared between age groups. RESULTS: A total of 14,479 participants were included in the study. Of these 3087 (21%) patients were older adults, 6071 (42%) were middle aged and 5321 (37%) were young adults. At presentation older adults were statistically different to the middle aged and younger adults for most characteristics measured (e.g. less intense back pain, more leg pain and more depression); however, the differences were small. The change in pain and disability over 12 months did not differ between age groups. CONCLUSIONS: This study found small baseline differences in older people with chronic LBP compared to middle aged and younger adults. There were no associations between age groups and the clinical course. SIGNIFICANCE: Small baseline differences exist in older people with chronic low back pain compared to middle aged and younger adults referred to secondary care for chronic low back pain. Older adults present with slightly less intense low back pain but slightly more intense leg pain. Changes in pain intensity and disability over a 12 month period were similar across all age groups.