Eugene O’Neill seems to have fostered a wavering estimation about the self- annihilating dreams and illusions of his characters. This particular characteristic of O’Neill has changed significantly during the progress of his career as a dramatist. The present study intends to show how far this attitude of O’Neill has changed. The study will examine three of O’Neill’s masterpieces and will try to trace the degree of change observable in his view of dreams and illusions of his characters. In The Hairy Ape O’Neill has handled the issue of dreams and illusions with a view to bringing the characters back to reality. In The Iceman Cometh his approach to dreams changes and this play portrays his characters as more inclined towards such dreams and it also marks the beginning form where O’Neill has changed his strategy. Finally, in Long Day’s Journey into Night O’Neill deals with the issue of dreams and illusions differently. At the beginning of his career his attitude towards such illusions and ‘pipe dreams’ was one of disapproval but towards the end of his career we notice that his understanding has changed and he acknowledges the necessity of such dreams and illusions as props and crutches in the lives of ordinary human beings.