The challenges faced by case managers when implementing case management have received little focus. Several qualitative studies have been published that may be able to shed light on those challenges. This study is a systematic review of qualitative literature to identify barriers case managers have when implementing case management. Five electronic bibliographic databases were systematically searched, and 10 qualitative studies were identified for inclusion in the review which were published from 2007 to 2016. Through thematic synthesis of findings, five themes were identified as barriers to case management implementation: unclear scope of practice, diverse and complex case management activities, insufficient training, poor collaboration with other health-care providers, and client relationship challenges. This review study suggested that standardized evidence-based practical protocols and certification programs may help overcome case managers’ barriers and improve case management practices. Health policymakers, case management associations, and health-care management researchers should develop educational and practical supports for case managers.