This is a case report and literature review involving congenital absence of the sternocleidomastoid muscle (SCM) and simultaneous herniation of the left lung into the neck. To date there have been eight cases of absence of the SCM muscle, but no records of lung herniation alone or in combination with SCM muscle absence. Included is the management course taken to correct this patient's defect, CAT scans of the neck, fluoroscopic imaging of the lung and neck, and photographic documentation of the defect.