Purpose: Patients with neurological diseases are potentially at high risk for developing deep venous thrombosis (DVT). We sought the prevalence and clinical background of patients with neurological diseases in whom DVT was detected during hospitalization. Methods: Consecutive patients admitted due to neurological diseases were prospectively registered. Those who were at risk for DVT were screened using venous duplex ultrasonography of the lower extremities. Predictors for DVT detection were analyzed. Results: During the study period, 192 of 785 patients received duplex ultrasonography. There were 34 patients with DVT identified (18%, age 63 +/- 17 years). Three patients had DVT in the popliteal or femoral vein and the others had below the knee; all of the DVT were asymptomatic. DVT was observed most frequently in patients with systemic vasculitis, followed by demyelinating disease. In patients with DVT, the median D-dimer level was 2.1 mu g/mL. On multiple logistic regression analysis, female ([odds ratio, 95% confidence interval] 3.2, 1.2-8.4), supine or sitting position for > 48 h (5.3, 1.8-15.0), D-dimer level >= 2.0 mu g/mL (6.2, 2.3-16.4), and white blood cell count >= 7,600 (4.2, 1.6-11.3) were independent predictors of DVT detection at the first screening ultra-sonography. DVT was detected in 1, asymptomatic pulmonary embolism was detected in 2, and both in 1 on chest computed tomography. Conclusion: DVT is not rare in patients with neurological diseases. Clinicians should be mindful of subclinical DVT in hospitalized neurological disease patients with decreased daily activity and elevated D-dimer levels or blood cell counts, especially in women.