Temporary lower-limb immobilisation following injury is a risk factor for the development of venous thromboembolism (VTE), which encompasses deep vein thrombosis (DVT) and pulmonary embolism. However, patients are not always risk-assessed for VTE in clinical practice and there is a lack of consensus among healthcare professionals on whether thromboprophylaxis should be offered and to whom. This article uses the fictional case study of a patient with an ankle fracture to explore the literature and guidance on VTE risk assessment and thromboprophylaxis in adults presenting to emergency settings with lower-limb trauma requiring immobilisation. It appears that it is important to consistently risk-assess patients and offer thromboprophylaxis to those deemed at moderate or high risk of VTE, since thromboprophylaxis is safe, efficacious and cost-effective in these patient groups.