Background <p>Practical and psychological barriers make it difficult for people with Suicidal Thoughts and Behaviors (STBs) to obtain professional help. Remote interventions have the potential to overcome many of these barriers, but the remote interventions to date have produced small or short-lived effects and only reduced suicidal thoughts, not behaviors. </p> Aims <p>This study therefore aims to evaluate the effectiveness of remotely delivered brief cognitive behavioral therapy for suicide prevention (BCBT) in preventing suicide attempts in a fully remote randomized controlled trial, in which it will be compared to an online self-help course that has previously been found to be effective in reducing suicidal thoughts.</p> Methods <p>A randomized controlled trial will be conducted in which 364 participants aged 16&#xa0;years and older will be recruited through the website of the Dutch suicide prevention helpline and randomized at a ratio of 1:1 to one of two interventions, both delivered via chat or phone. Participants in the experimental condition will receive BCBT. This intervention consists of approximately 12 sessions in which a narrative assessment of a recent suicidal crisis is used to create a personalized treatment plan out of several modules, such as cognitive restructuring, mindfulness and means restriction. Participants in the control group will receive a semiguided self-help course, which includes 6 lessons and 6 feedback sessions with a therapist, focusing predominantly on psychoeducation and cognitive restructuring. The primary outcome of the study is the number of suicide attempts, measured with the Columbia Suicide Severity Rating Scale (C-SSRS). Secondary outcomes are the self-reported severity of suicidal ideation, treatment satisfaction, adverse effects, and quality of life. All outcomes will be assessed at baseline, immediately after treatment and at 18-month follow-up.</p> Discussion <p>If remote BCBT proves effective, the findings of this study will add to the evidence base of BCBT as one of few replicated psychological interventions that can reduce suicide attempts and pave the way for the wider dissemination of this remote intervention.</p> Trial registration <p>Clinicaltrials.gov NCT06370104. Registered on April 8, 2024.</p>