We have evaluated the effect of enoxaparin, a potent antithrombotic drug, on bleomycin (Bleo) induced pulmonary inflammation in mice. Pulmonary injury was induced by a single intratracheal (IT) instillation of Bleo. Four groups of female C57BL/6 mice, each received one of four treatments: (1) IT Bleo and daily intraperitoneal (IP) injections of enoxaparin (EN) starting one day before IT instillation of Bleo (Bleo-EN); (2) IT Bleo and IP injections of saline (Bleo-Sal); (3) IT saline and IP enoxaparin (Sal-EN); (4) IT saline and IP saline (Sal-Sal). Animals were sacrificed 14 days after IT treatment. Lung injury was evaluated by analysis of bronchoalveolar lavage fluid and histologically by an overall semiquantitative index of lung injury and a quantitative image analysis assessing alveolar wall area fraction and fibrosis fraction. Treatment of mice with enoxaparin did not ameliorate Bleo induced lung injury. Our study does not establish a critical role of procoagulant activity in the evolution of Bleo-induced lung injury and does not support the use of antithrombotic therapy for the prevention of pulmonary fibrosis.