The purpose of this systematic review was an assessment of the efficacy of aftercare in chronic patients and the frail elderly when discharged from hospital, as regards quality of life, compliance, costs, medical consumption and quality of care. In pursuit of this goal, 17 publications on the effects of aftercare after discharge from hospital were examined. A systematic assessment of methodological quality by two blinded independent reviewers resulted in a consensus score (0-100 points), based on four categories: the study population, description of the interventions, measurement of the outcome and the analysis and presentation of the data. Only three of the 17 studies scored more than 50 points, indicating that most of the studies were of poor methodological quality. The most prevalent methodological problems were that co-interventions were not avoided, a placebo group was lacking, the assessment was not blinded and the analysis was not made on the basis of the intention-to-treat principle. The majority of the studies did not report clear beneficial effects in favour of the intervention group. The positive effects reported were limited to costs and quality of care.