The prevalence of radiological abnormalities of the sacroiliac joints, the manubriosternal joint, and the lumbar spine were assessed, and quantitative sacroiliac scintigraphy was performed in 151 patients with a history of chronic inflammatory back pain and in 31 controls with non-inflammatory back pain. Sacroiliitis was found in 124 patients (82%), manubriosternal lesions in 84 patients (56%), and lesions of the lumbar spine in 58 patients (38%). In 19 patients (13%), manubriosternal lesions provided the sole radiological abnormality and in five patients (3%) no radiological abnormality could be demonstrated at any of these sites. Quantitative sacroiliac scintigraphy showed increased values in 69 of 137 patients examined (50%), but also in 10 out of 12 control patients with disc degeneration (83%) and is, therefore, nonspecific for inflammatory lesions. Radiological examination of the manubriosternal joint is recommended in patients with inflammatory back pain without radiographic evidence of sacroiliitis.