Botulinum toxin (BTA) is very useful tool in the management of strabismus. BTA injection is rapid and relatively non-invasive. It may be repeated several times. It frequently produces complete cure or significant improvement. It also facilitates further preservative treatment with prism glasses, correcting strabismus angle, and carrying exercises of binocular vision. The mode of action starts with the blocking of acetylcholine release in presynaptic nerve endings in the neuromuscular junction, then it cause temporal paresis of the human extraocular muscles by chemodenervation, it then enables the antagonist muscles contraction. This produces an effect of permanent alignment change and also changes visual localization by dissociation of pathologic cortical pathways and anomalous retinal correspondence and enables development of new cortical pathways with normal retinal correspondence. This method is effective, especially in young child, as the achievement of eyes alignment in the binocular vision development process in infants facilitates fusion. It is used to assess whether diplopia will occur after squint surgery, to assess whether patient has useful binocular function. The major therapeutic use is in unrecovered VI nerve palsies, decompensated heterophoria, acute acquired esotropia, sensory strabismus, Nystagmus, etc. Botulinum toxin is administered on an outpatient basis to adults under local anesthesia, children may be sedated with ketamine or short-lasting inhalation anesthesia (sevofluran) in the operating theatre. The dose varies for all the indications. Some complications are subconjunctival hemorrhage, transient ptosis and dilated pupil.