Importance Elderly patients are underrepresented in clinical trials. Objective To identify barriers and strategies concerning recruitment and retention of elderly patients in clinical trials. Data Source MEDLINE (via PubMed), Cochrane Central Register of Controlled Trials (via Cochrane Library), Embase (via Ovid)Eligibility Publications stemming from original research that report on barriers of or strategies for better recruitment or retention of elderly people. Outcomes Barriers and strategies concerning recruitment and retention of elderly people in clinical trials.Critical Appraisal This study is about identifying barriers and solutions concerning recruitment and retention of elderly patients in clinical trials. Typical endpoints requiring a risk of bias appraisal such as ones that concern efficacy or safety will not be assessed, consequently, there will be no risk of bias assessments. Furthermore, a very heterogeneous set of studies will be included for which there exists no single risk of bias-assessment tool.