Frontal lobe syndrome (FLS) is a clinical picture caused by damages due to reasons like prefrontal cortex cerebrovascular disease, tumor, infection or head trauma and displaying itself through distinct and permanent personality, social adaptation, and behavior changes. A 13-year-old, right-handed male case was in deep coma for 1.5 months after a traffic accident 28 months ago. His brain tomography revealed fractures in right orbital floor and anterior skull base, subarachnoid hemorrhage, right frontal contusion, left frontal epidural hematoma and pneumo-cephalus. Two months after the accident, case could perform simple commands and was right hemiplegic and motor aphasic. Motor deficit was treated through rehabilitation. His family was complaining about his hoarseness, inattentiveness, forgetfulness, overeating, meaningless crying, itchiness, nervosity, aggressiveness, swearing, and repeating the same sentence. In the examination, he had partial time orientation, intermediate self-care, increased euphoric, psychomotor activity, labile and inappropriate affect, disinhibition, no insight, hoarse voice, foul language, near-far memory disorder and impaired reading, writing, calculating and judging compared to his peers. FLS was considered for the patient. This case was reported since his daily-life activities considerably deteriorated due to FLS remaining as sequellae despite full recovery in deep coma and motor deficit, developing after head trauma.