Purpose: To evaluate the incidence of inferior oblique inclusion during hooking of the lateral rectus muscle and how to detect and prevent.     Methods : 50 patients (80) eyes operated upon lateral rectus muscles(recession 55 eyes resection 25 eyes ) for correction of horizontal deviation (esotropia and exotropia) the incidence of inferior oblique inclusion during hooking of the lateral rectus muscle throw fornix conjunctival  incision was evaluated and managed.   Results: the incidence of inferior oblique inclusion was found in 17 eyes 21.25%(12 eyes 15% Partial inclusion and 5 eyes 6.25% total inclusion) the inclusion was detected and managed early. Post operatively no element of vertical deviation due to inferior oblique inclusion.   Conclusion: inferior oblique inclusion is a preventable complication if taken in consideration during hooking of the lateral rectus muscle.