As part of an interview survey of a defined population of 3,097 rural persons 65 years and older (the Iowa 65+ Rural Health Study), the prevalence and functional correlates of specifically defined low back pain were studied. Low back pain was reported by 23.6 per cent of the women and 18.4 per cent of the men in the year prior to the survey, with prevalence rates declining with age. Forty per cent of those with low back pain noted its presence at the time of the interview. Over half had used analgesics. Use of medical and chiropractic services for this symptom was nearly 75 per cent; 25 per cent had at least one hospitalization directly related to low back pain and over 5 per cent had low back surgery. Limitation of walking, sitting, bending over, and performing household chores was reported by 15 to 40 per cent, and 21 per cent attributed sleep disturbance to the low back pain. Nearly 75 per cent of subjects with low back pain reported first onset of the problem prior to age 65, which has important implications for pathogenesis and prevention. The functional and clinical burdens of low back pain in this population of rural elderly were substantial and require further evaluation of risk factors and impact on health status.J Am Geriatr Soc 33:23, 1985