Background Dedicated Health and Social Care Professional (HSCP) teams have been proposed for emergency departments (EDs) in an effort to improve patient and process outcomes. This systematic review synthesises the totality of evidence relating to the impact of early assessment and intervention by HSCP teams on quality, safety and effectiveness of care in the ED. Methods A systematic literature search was conducted in April 2019 to identify experimental studies examining the effectiveness of ED-based HSCP teams providing services to adults aged = 18 years old and including two or more of the following disciplines: occupational therapist, physiotherapist, medical social worker, clinical pharmacist, or speech and language therapist. Data extraction and quality appraisal of each study were conducted independently by two reviewers. Results Six studies were included in the review (n=273,886), all describing interdisciplinary Care Coordination Teams (CCTs) caring for adults aged = 65 years old. CCT care was associated with on average 2\% reduced rates of hospital admissions (three studies), improved referrals to community services for falls (one study), increased satisfaction (two studies) with the safety of discharge (patients and staff), and with the distribution of workload (staff), improved health-related quality of care (one study). No statistically significant differences between intervention and control groups emerged in terms of rates of ED re-visits, ranging between 0.2\% and 3\% (two studies); hospital length of stay (one hour difference noted in one study) or mortality rates (0.5\% difference in one study). Increased rates of unplanned hospitalisations following the intervention (13.9\% difference) were reported in one study. The methodological quality of the studies was mixed. Discussion We found limited and heterogeneous evidence on the impact of HSCP teams in the ED, suggesting a reduction in hospital admissions as well as improved patient and staff satisfaction. More robust investigations including cost-effectiveness evaluations are needed.