Procainamide is the commonest cause of a drug induced lupus syndrome. Long term administration of this compound may induce a variety of immunological abnormalities, including antinuclear antibodies. Uncommonly, 'lupus anticoagulants' have been demonstrated in the absence of other evidence of drug induced lupus. Details of a 67 year old man who developed not only drug induced lupus but also antiphospholipid antibodies which were associated with multiple pulmonary thromboemboli after the administration of procainamide are recorded.