Posteroanterior (PA) and lateral chest radiographs are performed as part of the routine staging and follow-up investigation of patients with malignant melanoma. We have assessed the contribution of the lateral chest radiograph in the follow-up of 227 consecutive patients with proven malignant melanoma. In only once case was an abnormality evident on the lateral radiograph which was not previously detected on the PA films. Our department, as a result of this study, has discontinued the routine use of lateral chest radiography in the follow-up of patients with malignant melanoma.