The Oxford-Family Planning Association contraceptive study includes 17,032 women, initially aged 25-39 years, recruited at 17 British family planning centers during the interval 1968-1974 and subsequently followed-up for periods up to 26 years. This article examines the pattern of referral to hospital for back disorders among these women. Certain back disorders have been reported to occur more frequently in oral contraceptive users than in other women, and back pain has also been reported in some women consequent to using an intrauterine device. The disorders considered were spinal osteoarthritis, displaced cervical disc, displaced lumbar disc, other and unspecified displaced disc, cervicalgia, unspecified back pain, and sprains and strains of the back. Spinal osteoarthritis and unspecified backache were the only two conditions significantly related (both positively) to age. Displaced lumbar disc and other and unspecified displaced disc were strongly positively related to height and weight. Unspecified backache showed similar, but less striking (in terms of the magnitude of the relative risks), associations with height and weight. Little evidence was found of any association between oral contraceptive use and any of the back disorders, and the same was true for intrauterine device use CONTRACEPTION 2000;60:331-335 (C) 2000 Elsevier Science Inc. All rights reserved.