Blunt chest trauma is an important clinical problem leading to injury of heart, lungs and other intrathoracic organs. However, some aspects of the pathophysiology of this kind of injury are poorly understood. In this experimental study, we aimed to establish a new model of unilateral blunt chest trauma in rats and to characterize its effects on cardiopulmonary physiology, hemodynamics and intrathoracic organs. The rats were separated into five groups and each group contained ten rats. In the control group, no blast trauma was delivered. The second, third and fourth groups were groups of mild intensity, moderate intensity and severe intensity trauma groups, respectively. The last group, fifth group, was the survivor group, and a light blast trauma was applied to this group like Group II. Basic cardiopulmonary parameters (heart rate, breath rate and SpO₂) were monitorized and recorded during the first 120 minutes. Gross and histological examinations of the lungs were performed and statistical analysis was performed. The cardiovasculary response to the injury was bradycardia in the light injury group and tachycardia in the moderate injury group. The pulmonary response was decreased SpO₂ and the lung contusion was the most common pathology in all trauma groups. This study established a useful model for the study of blunt trauma in small animals. Lung contusion more obviously occurred than other pathologies and some forms of ventilation and perfusion mismatch took role in all trauma cases. The associated injuries were related with high mortality rates.