Infection of the temporomandibular joint (TMJ) is a rare pediatric condition resulting from the introduction of pathogens into the joint by hematogenous seeding, local extension, or trauma. Early recognition of the typical signs and symptoms including fever, trismus, preauricular swelling, and TMJ region tenderness are critical in order to initiate further evaluation and prevent feared complications of fibrosis, ankylosis, abnormal facial structure, or persistence of symptoms. Contrast-enhanced computed tomography with ancillary laboratory analysis including erythrocyte sedimentation rate, C-reactive protein, and white blood cell count are beneficial in confirming the suspected diagnosis and monitoring response to therapy. Initial intervention should include empiric parenteral antibiotics, early mandibular mobilization, and joint decompression to provide synovial fluid for analysis including cultures. This report describes a case of TMJ bacterial arthritis in a healthy 6-year-old male who was promptly treated nonsurgically with intravenous antibiotics and localized needle joint decompression with return to normal function after completion of oral antibiotics and physical therapy.