When the neck muscles are swollen and hardened due to congenital squint in children, the child’s head is tilted to the diseased side and the chin is turned to the opposite side, which can be present after birth but usually appears 2 to 3 weeks after birth. On palpation, a hard, painless pyknotic swelling can be found in the sternocleidomastoid muscle on the affected side, which gradually increases in size as large as the end of the adult thumb within 2 to 4 weeks and then begins to recede, gradually disappearing within 2 to 6 months. The majority of patients do not retain a sloping neck; in a few cases, the distal segment of the muscle is replaced by a fibrous cord and the head is deflected to the affected side due to the pull of the contracted muscle. The head and face can be deformed secondary to the abnormal position, the side with shortened muscles, the affected side becomes shorter in length, the face widens, and the face becomes more asymmetrical due to gravity and the growth of the bones. Both eyes and ears are not in the same plane. These defects are not obvious when the head is tilted, but the deformity is prominent when the head and neck are squared. The non-parallelism of the eyes can cause visual fatigue. The facial asymmetry is aggravated with skeletal development. The deep cervical fascia, broad cervical muscle, and oblique angle muscle can be contracted, and the carotid sheath and blood vessels can also be contracted. Finally, the skull develops asymmetrically, and the cervical and upper thoracic vertebrae develop a lateral bending deformity with the concave side of the curvature facing the affected side. If the deformity is not corrected, the soft tissue on the affected side shortens with growth and development. The deep fascia of the neck thickens and tightens. Later, the carotid sheath and the vessels within the sheath also become shorter. In this case, even after the contracted sternocleidomastoid muscle is released, the above-mentioned consequences become the cause of the oblique neck, making the correction of the deformity unsatisfactory. Occasionally, sternocleidomastoid muscle fibrosis is not the cause of the squint, and there are reports of squint due to contracture of the anterior trapezius muscle and shortening of the scapulolingual muscle. The latter may be accompanied by pulling of the larynx and trachea to the affected side. Bilateral squint is rare, with the neck appearing shortened at the midline, chin elevation, and upward facial tilt. The diagnosis is usually not difficult based on the above-mentioned presenting features. The swelling and stiffening of neck muscles due to congenital squint in children needs to be differentiated from pediatric ossifying myositis, polymyositis, fibro-weaving myositis, dermatomyositis, and generalized calcification.