AIMS: This review aims to classify the evidence from randomised controlled trials (RCTs) on mental health services (MHS) for people with serious mental illness (SMI) available in the Cochrane Schizophrenia Group's (CSzG) specialised register. DESIGN: Scoping review. METHODS: We retrieved and screened RCTs of service-level interventions considering non-pharmacological approaches for mental healthcare of the CSzG register. We classified and collected the main characteristics of the RCTs using a customised data extraction and charting form based on DESDE-LTS classification. RESULTS: We included 233 out of 262 total trial registries. Most of the studies were conducted in China, 136 (58%), 57 (24%) North America and 26 (11%) Europe. We classified the studies as ambulatory assistance 80 (34%), day services/out-patient care 38 (16%), residential services 44 (19%), accessibility to care 19 (8%), information/assessment 39 (17%), self-help and voluntary help 10 (4%), e-health 52 (22%), and discharge services 17 (7%). CONCLUSIONS: We found a large number of trials that investigated the effects of mental health services for people with SMI. Trials classification was difficult due to the poor report of the characteristics of these complex interventions. This database can be used to plan and prioritise systematic reviews according to the needs of stakeholders. RELEVANCE STATEMENT: The study is of interest to mental health nursing because it studies the different services in which nurses play a fundamental role with implications in the nursing practice, education, research or leadership and management.