Background: People with mental health crises may need intensive care support that, in many countries, implies a psychiatric hospitalization that may negatively affect the individual. Furthermore, it involves the individuals’ removal from their daily spaces, which implies an adaptive effort when returning to the community. In order to reduce the treatment’s impact of a mental health crisis, Crisis Resolution or Home Treatment (CRHT) Teams have been providing an alternative to inpatient treatment. Aim: To analyze and highlight CRHT teams’ effectiveness in reducing days of treatment, relapse, and rehospitalization of adults (18-65 years) compared to treatment as usual defined as inpatient treatment. Methods: We will develop a systematic review of the current literature by the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2019 Statement. Two authors will independently conduct study inclusion, data extraction, quality, and bias risk assessments. We will include experimental study designs like randomized clinical trials, non-randomized, quasi-experimental, before and after studies, prospective and retrospective cohort studies, and case-control studies involving working-age adults (18-65 years) irrespective of culture, ethnicity, or mental health diagnosis. Results: We will include primary outcomes like days of treatment, relapse (as defined by each study), and rehospitalization. Secondary outcomes will be service user satisfaction, dropout rate, and the proportion of patients with adverse events (suicide, self-harm, or aggression/violence). Conclusions: This study will allow evidence to determine the need to create and encourage the implementation of CRHT teams to provide an effective alternative response to psychiatric hospitalization.