The objective was to identify the correlation between the sign of lower limb swelling and unilateral deep vein thrombosis (DVT) in patients with brain lesions. A total of 194 patients, between May 12th, 2011 and December 30th, 2015, who had initially elevated plasma D-dimer level (> 0.55 mg/L) and underwent enhanced DVT computed tomography (CT) were recruited in this study. The circumference of bilateral lower limbs in CT image, below 10 cm and above 15 cm from the prominence of tibial tuberosity, were measured by a single intra-observer using NIH ImageJ software. The difference of 2 cm or more between both sides was considered as significant swelling. We also evaluated patients' range of mobility and cognitive function and its relation to lower limb swelling in DVT in patients with brain lesions. Thirty-five patients were diagnosed with DVT. The presence of lower limb swelling was not statistically significant between patients with DVT and those without DVT in the proximal limb (p = 0.330) and distal limb (p = 0.405). In DVT patients (n = 35), there was no statistically significant correlation between lower limb swelling and other covariates of the patient group. There was no statistically significant correlation between lower limb circumference and DVT.