To determine (1) the frequency of osteoporosis at the hip and lumbar spine in a postpolio clinic population and (2) the association of lower-extremity muscle strength and other potential contributing factors to osteoporosis with bone density measured at the hip.Cross-sectional study involving a chart review.A university-affiliated hospital postpolio clinic.Patient charts (N=379) were reviewed; 164 (26%) were included, and 215 (74%) were not included primarily (74%) because of the unavailability of bone density results.Not applicable.Bone density (in g/cm(2)) and T score were assessed at the femoral neck and lumbar spine. Muscle strength was evaluated by manual muscle testing in 7 bilateral lower-extremity muscles.The occurrence of osteoporosis at the hip and lumbar spine was 20 (32%) of 62 and 6 (10%) of 61 in men, 3 (9%) of 33 and 2 (6%) of 32 in premenopausal women, and 18 (27%) of 67 and 7 (11%) of 65 in postmenopausal women, respectively. In a logistic regression model, the presence of osteoporosis at the hip was significantly associated with strength sum score in the same extremity in which the bone density was performed after adjusting for other important risk factors (age, body mass index, time since polio).Osteoporosis occurred commonly at the hip in a postpolio clinic population. Hip bone density was associated with muscle strength in the same lower extremity.