The predictive power of clinical symptoms in the diagnosis of deep venous thrombosis (DVT) was assessed using a retrospective design. The sample consisted of 61 rehabilitation patients who were referred for Doppler ultrasonography. Patients had a mean age of 60.6 (standard deviation, 18.4) years. Clinical measures documenting presence of swelling, warmth, fever, and lower limb asymmetry (> 2.5 cm) were correlated with the outcome of venous duplex Doppler examinations. Clinical symptoms had low sensitivity (0.07-0.33) but generally higher specificity (0.76-0.85) for DVT. Positive predictive power was lowest for fever (0.08) and highest for swelling (0.66). Prevalence rates for DVT were greatest (0.41) in patients presenting with multiple symptoms. Results suggest clinical predictors of DVT remain elusive. A high rate of false-positives based on clinical findings from examination is acceptable given the low risk associated with ultrasonography and the clear benefit of early diagnosis of DVT.