Background: The AID-ICU trial aims to assess the benefits and harms of haloperidol for the treatment of delirium in acutely admitted, adult intensive care unit (ICU) patients. This paper describes the detailed statistical analysis plan for the primary publication of results from the AID-ICU trial. Methods: The AID-ICU trial is an investigator-initiated, pragmatic, international, multicentre, randomized, blinded, parallel-group trial allocating 1000 adult ICU patients with manifest delirium 1:1 to haloperidol or placebo. The primary outcome measure is days alive and out of hospital within 90 days post-randomization. Secondary outcome measures are days alive without delirium or coma, serious adverse reactions (SARs) to haloperidol, use of escape medicine, days alive without mechanical ventilation, and mortality, health-related quality-of-life measures and cognitive function 1-year post-randomization. Statistical analysis will be conducted in accordance with the current pre-specified statistical analysis plan. One formal interim analysis will be performed. The primary outcome will be adjusted for stratification variables (site and delirium motor subtype) and compared between treatment groups using a likelihood ratio test described by Jensen et al A secondary analysis will be conducted with additional adjustment of the primary outcome for prognostic variables at baseline. The primary conclusion of the trial will be based on the intention-to-treat analysis of the primary outcome adjusted for stratification variables. Conclusion: The AID-ICU trial will provide important, high-quality data on the benefits and harms of treatment with haloperidol in acutely admitted, adult patients with manifest delirium in the ICU.