BACKGROUND: Central venous access devices (CVADs) can have high rates of failure due to dressing-related complications. CVADs placed in the internal jugular vein are at particular risk of dressing failure-related complications, including catheter-associated bloodstream infection and medical adhesive-related skin injury. Application of Mastisol liquid adhesive (MLA) may reduce CVAD dressing failure and associated complications, by reducing the frequency of dressing changes. The aim of this study is to investigate whether, in an intensive care unit (ICU) population, standard dressing care with or without the addition of MLA, improves internal jugular CVAD dressing adherence. METHODS: This two-arm, parallel group randomised controlled trial will be conducted in three Australian ICUs. A total of 160 patients (80 per group) will be enrolled in accordance with study inclusion and exclusion criteria. Patients will be randomised to receive either (1) 'standard' (in accordance with local hospital policy) CVAD dressings (control) or (2) 'standard' dressings in addition to MLA (intervention). Patients will be followed from the time of CVAD insertion to 48 h after CVAD removal. The primary outcome is 'dressing failure' defined as requirement for initial CVAD dressing to be replaced prior to seven days (routine replacement). DISCUSSION: This study will be the first randomised controlled trial to evaluate the clinical effectiveness of MLA in the adult intensive care unit population and will also provide crucial data for patient-important outcomes such as infection and skin injury. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12621001012864 . Registered on 2 August 2021.