To investigate the indications, safety and efficacy of catheter directed thrombolysis for early left lower extremity deep venous thrombosis (DVT) without vena cava filters protection. Clinical data of 54 cases of early left lower extremity DVT received catheter directed thrombolysis without vena cava filters from July 2008 to June 2010 were retrospectively analyzed. The thrombosis was entire without free floating clots and no thrombosis in vena cava detected with ultrasound scan. Twenty-five patients were male and 29 were female with the average age of 52.8 years. Fifty-one of which were iliofemoral and popliteal, the other 3 were iliofemoral. The course were ≤ 7 d in 45 cases and these were 8 to 30 d in 9 cases. Urokinase of 300 000 U was infused through catheters per 2 h twice a day. Meanwhile 4000 U of low weight heparin was administered subcutaneously per 12 h, or heparin infusion at dosage of 18 U×kg(-1)×h(-1). The procedure technically succeeded in all patients. In total cases venous score decreased to 4.6 ± 2.1 post 6 to 10 d of thrombolysis from 10.8 ± 1.0 with thrombolysis rate of 58% ± 18% which was not significantly different between groups of ≤ 7 d and 8 to 30 d (t = 1.02, P = 0.34). On 14(th) day, 11 patients (20.4%) completely recovered, 35 cases (64.8%) experienced large improvement, 8 patients (14.8%) had mild improvement and nobody was failed, resulting in total efficacy of 100%. No patient developed clinical symptomatic pulmonary embolism. SpO2 did not alter markedly post thrombolysis [(91.0 ± 2.6)% vs. (90.8 ± 2.4)%, t = 2.03, P = 0.05]. No patients suffered from cerebral hemorrhage and haemoturia, and catheter induced inflammation occurred in 4 cases (7.41%). There was mild bleeding in puncture sites in 11 patients (20.4%) during the course. There were 36 patients (66.7%) had been followed up with the time of 6 to 21 months. In which 31 cases had no lower extremity edema or had mild edema after activities. Two patients developed serious edema after activities for deep venous insufficiency. Three cases combined with malignant tumor or renal failure recurred. For early left extremity DVT which is entire without free floating clots and no thrombosis in vena cava, catheter directed thrombolysis without filter protection maybe administered with safety, efficiency and lower expense.