Background: Teamcare should, like all patient care, also contribute to evidence-based practice (EBP). Randomized controlled trials (RCTs) focusing on teamcare have been performed but no study has addressed its essentials. How far this EBP has progressed in different health aspects is generally established in systematic reviews of RCTs. Aim: The aim is to determine the essentials of teamcare including the nurse profession in RCTs of multi- or interdisciplinary interventions in somatic care focusing on the stated context, goals, strategies, content as well as effectiveness of quality of care. Methods: A systematic review was performed according to Cochrane review assumptions to identify, appraise and synthesize all empirical evidence meeting pre-specified eligibility criteria. The PRISMA statement guided the data selection process of 27 articles from PubMed and CINAHL. Results: Eighty-five percent of RCTs in somatic care showed a positive effectiveness of teamcare interventions, of which interdisciplinary ones showed a greater effectiveness compared with the multidisciplinary approach (100% vs 76%). Also theory-based RCTs presented higher positive effectiveness (85%) compared with non-theory-based RCTs (79%). The RCTs with positive effectiveness showed greater levels for professional-centered ambition in terms of goals and for team-directed initiatives in terms of strategy, and a significantly higher level for patient-team interaction plans in terms of content was shown. Conclusions: Teamcare RCTs are still grounded in the multidisciplinary approach having a professional-centered ambition while interdisciplinary approaches especially those that are theory-based appear to be essential with regard to positive effectiveness and preferable when person-centered careis applied.