Botulinum toxin type A (BTX-A) inhibits muscle contraction, which leads to reversible muscle atrophy and paralysis. Therefore, BTX-A injection can be an effective treatment of facial asymmetry that originated from the uncoordinated muscle movement. A 52-year-old patient was referred from another hospital for the correction of post-traumatic sequelae. The patient had prominent scar in the mandibular symphysis area with asymmetric lower lip movement. The reason for this asymmetric lower lip movement was due to damage in the lower lip depressor muscle. After the injection of BTX-A on the lower lip depressors, asymmetric lip movement has been improved.