The masseteric space is an important tissue compartment of the neck, but disease in it is difficult to diagnose and treat. In this paper a case of a young adult male with an abscess of the submasseteric space is presented. Diagnosis was established by computed tomography (CT) of the neck, but the severity of the lesion was not accurately estimated. Surgical intervention was performed and a large quantity of pus was drained. A detailed medical history and clinical examination of the patient as well as CT are important tools in the accurate diagnosis and efficient treatment of the disease.