Posttraumatic pulmonary pseudocyst is a rare complication of blunt thoracic trauma. It is commonly seen in pediatric and young adult patients. In the literature, traumatic pseudocysts are also defined as pseudocystic hematoma, traumatic lung cavity and traumatic pneumatocele. Traumatic pseudocysts usually have good clinical prognosis, recover spontaneously with supportive treatment and do not require surgery. In this report, we present rare cases of two posttraumatic pulmonary pseudocysts developed after traffic accidents, where conservative treatment contributed excellent outcomes.