OBJECTIVE: To internationally validate a tool for predicting the risk of delayed healing of venous leg ulcers (VLUs). METHOD: A 10-item tool including sociodemographic factors, venous history, ulcer and lower limb characteristics, compression and mobility items to determine the risk of delayed healing of VLUs has previously been developed and validated in Australia. This study prospectively validated this tool using receiver operating characteristic (ROC) methods; using the area under the curve (AUC) to quantify the discriminatory capability of the tool to analyse the international populations of the UK, Austria and New Zealand. RESULTS: The validation of the tool in the UK, Austria and New Zealand has indicated that the model has moderate discrimination and goodness-of-fit with an AUC of 0.74 (95% CI: 0.66-0.82) for the total risk assessment score. CONCLUSION: The international validation of a risk assessment tool for delayed healing of VLUs will allow clinicians globally to be able to determine realistic outcomes from an early assessment and to be able to guide early tailored interventions to address the specific modifiable risk factors and thus promote timely healing.