The aim of this study was to decide whether shoulder pain in stroke is a marker of severity, or an independent predictor of poor outcome. The study was prospective observational in design from consecutive admissions. Acute medical and geriatric wards in three district hospitals provided the setting, and the subjects were 76 patients acutely admitted to hospital with a first stroke. The main outcomes measured were length of stay in hospital, Barthel Index, Frenchay Arm Test, Motricity Index and discharge placement. After controlling for other indicators of stroke severity, shoulder pain on movement was the most important predictor of poor recovery of arm power and function, and an important contributor to length of stay in hospital. Urinary incontinence was the strongest indicator of length of stay and Barthel Index scores. Patients with subluxation and malalignment of the shoulder fared much more poorly than those with normal shoulder alignment. The results concluded that shoulder pain appears to influence outcome of stroke independent of severity. We recommend that this symptom receive careful attention.