population-based Copenhagen Stroke Study, it was found that on admission 32% of the stroke patients had severe arm paresis and 37% had mild arm paresis. 1 In 64 (13%) out of 491 surviving patients, the affected arm remained entirely a-functional, despite the efforts of a comprehensive rehabilitation programme. These patients accounted for 25% of the total number of bed-days for all 491 patients. 2 In recent Objective: Assessment of the available evidence for the effectiveness of exercise therapy to improve arm function in patients who have suffered from a stroke. Methods: A systematic search of bibliographical databases and reference checking were performed to identify publications on randomized controlled trials (RCTs) which evaluated the effect of exercise therapy on arm function in stroke patients. The methodological quality was assessed systematically by two raters, based on a standardized list of methodological criteria. Study characteristics, such as the chronicity and severity of impairment of the patient population, the amount and duration of interventions, and specific methodological criteria, were related to reported effects.