The correlation of roentgenographic findings, clinical history, and incipient disc degeneration (DD), diagnosed with magnetic resonance imaging, was analyzed in young patients with low-back pain (LBP). One or more lumbar discs were abnormal in 57% of the 20-year-old LBP patients (n = 75) and in 35% of the asymptomatic controls (n = 34) in MRI. Narrowed disc spaces and alterations attributed to lumbar Scheuermann's disease, shown on the radiographs, were always associated with DD in MRI. Such a strong relationship was not observed with transitional vertebrae, spondylolisthesis, spina bifida, or postural abnormalities. However, an increased weight, a positive straight leg raising test, and a reduced lumbar mobility was consistent with an increase in frequency of DD. Magnetic resonance imaging is a safe and sensitive method for studying the presence and etiologic factors of DD.