Health and social care professionals' competencies have traditionally been separated because of the different aims of the two professions. These competencies need to be integrated, to make sure that seamless services are provided that meet the often complex needs of patients and clients in a coordinated and timely way. The aim of this integrative review was to identify, describe and synthetise previous studies on integrated competencies in health and social care. Electronic literature searches were carried out on the CINAHL, ProQuest, PsycInfo, PubMed, Scopus and SocIndex databases for peer-reviewed scientific papers that were published in English between 1 January 2007 and 31 December 2019. This identified 3,231 papers, after duplicates were removed, and 18 focused on the integration of social workers' competencies with health care. Other types of integration were not found. The value added by integrating social workers' competencies with health care focused on engaging working orientation, improving communication with family members, increasing understanding of service resources and mastering successful discharge procedures so that they met comprehensive, complex health and well-being needs. Social workers added value when they worked with multi-professional teams, but there were challenges to integrating competencies and these were related to professional collaboration and fragmented leadership. In future, more attention needs to be paid to diversifying and optimising the integration of professional health and social care competencies that meet clients' and patients' care and service needs. It is also vital to focus on developing the professional and leadership strategies that are needed to combine those competencies.