The risk of deep vein thrombosis (DVT) and pulmonary embolism (PE) is well documented in patients following cast immobilisation for injuries of lower extremities. There are no generally accepted approaches to preventing this complication and hence there remains substantial practice variation amongst surgeons regarding the use of anticoagulation measures. The present survey was conducted to investigate the current chemothromboprophylaxis practice among UK orthopaedic departments for patients immobilised with plasters for lower extremity injuries and establish any variations in practice. A telephone questionnaire survey was conducted on junior doctors (Senior House Officers and Registrars) in orthopaedic departments of 70 randomly selected hospitals in United Kingdom. This survey assessed the thromboprophylaxis practice for lower limb injuries in plaster casts. Our results show substantial variation amongst British orthopaedic surgeons in the use of chemothromboprophylaxis measures. Sixty-two percent of the departments do not use any DVT prophylaxis in this group of trauma. Furthermore, only 11.4% of the departments performed risk stratification on their patients. Ninety-nine percent of the respondents were unaware of any existing guidelines in this regard. Although the incidence of DVT in patients in plaster for lower extremity injuries is low compared to the Hip/Knee arthroplasty group, this is not insignificant. Both over and under treatment with thromboprophylaxis can have implications in terms of side effects and costs. One possible solution is to use risk stratification to identify individuals who are likely to benefit from prophylaxis. There is a substantial variation and inconsistency in practice among orthopaedic departments in United Kingdom due to a lack of clinical guidelines in this group of trauma and it remains underused even in high-risk group.