Abstract Background Many strategies have been designed and evaluated to address poor hand hygiene compliance. Unfortunately, well-designed economic evaluations of hand hygiene improvement strategies are lacking. Objective To compare the cost-effectiveness of two successful implementation strategies for improving nurses’ hand hygiene compliance and reducing hospital acquired infections (HAI's). Design and setting A cost-effectiveness analysis alongside a cluster randomised controlled trial was conducted in 67 nursing wards of three hospitals in the Netherlands. The evaluation used a hospital perspective. Participants All affiliated nurses of the nursing wards. Wards were randomly assigned to either the control group (n=30) or the experimental group (n=37). Methods The control group received a state-of-the-art strategy including education, reminders feedback and optimising materials and facilities. The experimental group received a team and leaders-directed strategy which included all elements of the state-of-the-art strategy supplemented with interventions aimed at the social context of teams and enhancing leadership. The most efficient implementation strategy was determined by the incremental cost-effectiveness ratio per extra percentage of hand hygiene compliance gained and the incremental cost-effectiveness ratio per additional percentage reduction in the HAI rate. Bootstrap methods were used to determine confidence intervals for these incremental cost-effectiveness ratio's. Two scenarios of 15 and 30% were used to express the association between increased hand hygiene compliance and the reduction in HAIs. Results The team and leaders-directed strategy was significantly more effective in improving hand hygiene compliance. The mean difference effect was 8.91% (95% CI, 0.75–17.06). This extra increase was achieved at an average cost of €5497 per ward. The incremental cost per extra percentage of hand hygiene gained on ward level was €622. The incremental cost per additional percentage reduction in the HAI rate on ward level was €2074 (30% scenario) and €4125 (15% scenario). Within the 30% scenario, there is a probability of 90% that the team and leaders-directed strategy is cost-effective and within the 15% scenario, there is a probability of 70% that the team and leaders-directed strategy is cost-effective. Conclusions Optimising hand hygiene compliance through a team and leaders-directed strategy is cost-effective as compared to a state-of-the-art strategy.