Introduction: Pulmonary embolism is the most common preventable cause of hospital death and is the number one strategy for improving patient safety in the hospital (Geerts et al., 2004). VTE is common among hospitalized patients and is found at least as frequently among medical as surgical patients (Bergmann and Kher 2005). Few studies have reported the frequency of VTE in medical patients, especially in intensive care, although approximately 75% of fatal VTEs occur among acute non-surgical patients (Bosker 2001, and Leizorovicz et al., 2004). VTE contributes to approximately 10% of all hospital deaths and there are variable reports of fatal VTE events in hospital ranging from 5-10% to 12-25% ( Simonneau et al., 1997 , Heit et al., 1999, and Cohen and Alikhan, 2001). The absolute risk of DVT in hospitalized patients was 10–20% in medical patients and 10–80% in critically ill patients (Greets et al., 2004). review of 1231 patients treated for VTE, 96% had at least one recognized risk factor. The risk increases in proportion to the number of predisposing factors (Anderson and Spencer 2003). In ICU patients, risk factors for VTE include, among others, illnesses requiring intensive care, immobilization for at least three days, previous VTE, old age, cancer, CHF, and indwelling vascular catheters. All these risk factors are present in acutely decompensated COPD patients (Leizorovicz and Mismetti 2004). There is a notable absence of guidelines for the prevention of VTE in these critically ill patients (Greets and Selby 2003). Many reports have documented that thromboprophylaxis is underutilized in critically ill patients, in contrast to its practice in surgical departments (Campbell et al., 2001, Rahim et al., 2003, and Stark and Kilzer 2004). The importance...... half of the paper ......d patients compared to the naïve group. No significant difference was found regarding the duration of mechanical ventilation. The in-hospital mortality rate was significantly lower in the enoxaparin-treated groups (Tables 2, 3, 4 and 5). Bosson et al, 2003 found that thromboprophylaxis significantly reduced hospitalization time and hospital mortality. They reported that the mortality rate was 3.8% in patients with DVT and 38.9% in those with PE. In contrast, the mortality rate was not significantly different between patients with thromboprophylaxis and those with no difference in LOS (Gardund, 1996 and Bergmann and Kher 2005). From previous results; it can be concluded that thromboprophylaxis in acutely decompensated COPD patients admitted to intensive care with standard prophylactic dose of enoxaparin is highly advisable, screening for DVT by DUS is essential in such circumstances and the fear