Pollution by particulates has consistently been associated with increased cardiorespiratory morbidity and mortality. It has been suggested that ultrafine particles, of which diesel exhaust particles (DEP) are significant contributors, are able to translocate from the airways into the bloodstream in vivo. In the present study, we assessed the effect of systemic administration of DEP on cardiovascular and respiratory parameters. DEP were administered into the tail vein of rats and heart rate, blood pressure, blood platelet activation, and lung inflammation were studied, 24 h later. Doses of 0.02, 0.1 or 0.5 mg DEP/kg (8, 42 or 212 µg DEP/rat) induced a significant decrease of heart rate and blood pressure, compared to saline treated rats. While the number of platelets was not affected, all the doses of DEP caused a shortening of the bleeding time. Similarly, in addition to triggering lung oedema, the bronchoalvealar lavage analysis revealed the presence of neutrophil influx in DEP-treated rats, in a dose-dependent manner. We conclude that the presence of DEP in the systemic circulation leads not only to cardiovascular and haemostatic changes but it also triggers pulmonary inflammation.