SUMMARY Pulmonary hypertension in systemic lupus erythematosus (SLE) in the absence of chronic parenchymal lung disease or pulmonary emboli is rare. We report such a case with an acute and rapidly progressive onset of symptoms in a patient who had started taking the contraceptive pill eight months previously.A 22-year-old woman presented with a three-week history of increasing dyspnoea, pleuritic pain, and a skin rash. Three years previously she had an isolated episode of acute arthritis affecting some of the small joints of the hands and feet, which terminated spontaneously after one week. She remained well and had a normal first pregnancy, after which she started taking the contraceptive pill Eugynon 30 (ethinyloestradiol 30 gg, levonorgestrel 250 Rg) for the first time.Nine months later she was admitted to hospital looking extremely ill, dyspnoeic, centrally cyanosed, pyrexic, and she had a widespread vasculitic rash. Marked right ventricular hypertrophy and failure were evident, and on auscultation there was a loud pericardial rub.Haematological investigations showed: Hb 13-6