Back pain is a common complaint of individuals with cystic fibrosis (CF). We studied back pain in our patient population in three ways: a questionnaire, an orthopedic evaluation, and a survey of chest roentgenograms. Forty-seven patients with CF reported back pain as compared with seven controls. Patients with CF showed decreased muscle strength and mobility in the trunk, chest, and shoulders. The incidence of structural kyphosis was only 8.7%, but many had vertebral wedging. Much of the back pain may be due to postural abnormalities or to vertebral wedging, not fixed structural kyphosis.