Introduction: Over 70% of all hospital admissions have a peripheral intravenous device (PIV) inserted; however, the failure rate of PIVs is unacceptably high, with up to 69% of these devices failing before treatment is complete. Failure can be due to dislodgement, phlebitis, occlusion/infiltration and/or infection. This results in interrupted medical therapy; painful phlebitis and reinsertions; increased hospital length of stay, morbidity and mortality from infections; and wasted medical/nursing time. Appropriate PIV dressing and securement may prevent many cases of PIV failure, but little comparative data exist regarding the efficacy of various PIV dressing and securement methods. This trial will investigate the clinical and cost-effectiveness of 4 methods of PIV dressing and securement in preventing PIV failure. Methods and analysis: A multicentre, parallel group, superiority randomised controlled trial with 4 arms, 3 experimental groups (tissue adhesive, bordered polyurethane dressing, sutureless securement device) and 1 control (standard polyurethane dressing) is planned. There will be a 3-year recruitment of 1708 adult patients, with allocation concealment until randomisation by a centralised web-based service. The primary outcome is PIV failure which includes any of: dislodgement, occlusion/infiltration, phlebitis and infection. Secondary outcomes include: types of PIV failure, PIV dwell time, costs, device colonisation, skin colonisation, patient and staff satisfaction. Relative incidence rates of device failure per 100 devices and per 1000 device days with 95% CIs will summarise the impact of each dressing, and test differences between groups. Kaplan-Meier survival curves (with log-rank Mantel-Cox test) will compare device failure over time. p Values of <0.05 will be considered significant. Secondary end points will be compared between groups using parametric or non-parametric techniques appropriate to level of measurement.