We report the pulmonary computed tomography (CT) findings in three patients with acute promyelocytic leukaemia who developed the retinoic acid syndrome following all-trans retinoic acid (ATRA) therapy. The most consistent CT findings were small, irregular peripheral nodules in the lung fields and pleural effusions. Two of the patients also showed evidence of reticular and ground glass shadowing as well as abnormal anterior mediastinal soft tissue. We report for the first time an association between ATRA and pneumothorax. We conclude that routine CT scanning may provide a sensitive means of early detection or monitoring of the syndrome and thereby may facilitate its management.