INTRODUCTION:Crisis resolution teams (CRTs) provide assessment and intensive home treatment in a crisis, aiming to offer an alternative for people who would otherwise require a psychiatric inpatient admission. They are available in most areas in England. Despite some evidence for their clinical and cost-effectiveness, recurrent concerns are expressed regarding discontinuity with other services and lack of focus on preventing future relapse and readmission to acute care. Currently evidence on how to prevent readmissions to acute care is limited. Self-management interventions, involving supporting service users in recognising and managing signs of their own illness and in actively planning their recovery, have some supporting evidence, but have not been tested as a means of preventing readmission to acute care in people leaving community crisis care. We thus proposed the current study to test the effectiveness of such an intervention. We selected peer support workers as the preferred staff to deliver such an intervention, as they are well-placed to model and encourage active and autonomous recovery from mental health problems. METHODS AND ANALYSIS:The CORE (CRT Optimisation and Relapse Prevention) self-management trial compares the effectiveness of a peer-provided self-management intervention for people leaving CRT care, with treatment as usual supplemented by a booklet on self-management. The planned sample is 440 participants, including 40 participants in an internal pilot. The primary outcome measure is whether participants are readmitted to acute care over 1 year of follow-up following entry to the trial. Secondary outcomes include self-rated recovery at 4 and at 18 months following trial entry, measured using the Questionnaire on the Process of Recovery. Analysis will follow an intention to treatment principle. Random effects logistic regression modelling with adjustment for clustering by peer support worker will be used to test the primary hypothesis. ETHICS AND DISSEMINATION:The CORE self-management trial was approved by the London Camden and Islington Research Ethics Committee (REC ref: 12/LO/0988). A Trial Steering Committee and Data Monitoring Committee oversee the progress of the study. We will report on the results of the clinical trial, as well as on the characteristics of the participants and their associations with relapse. TRIAL REGISTRATION NUMBER:ISRCTN 01027104;pre-results stage.