tennessee williams (1911-1983), the modern american dramatist, had his own unique school of dramaturgy. the dramas which he depicted are populated by characters who are lonely, desperate, in anxiety, alienated and in one word lost. they face challenges which they may overcome or not, through the choices they make. all these moods and conditions are clearly seen and explained in the theory of existentialism, hence williams’ inspiration from this philosophy. the aim of this thesis is to deal with two of williams’ major dramas, the glass menagerie and a streetcar named desire, in the light of existentialism and specifically kierkegaard’s theory of existence. kierkegaard counts three levels of existence, and each level is characterized by specific moods and conditions. it will be tried to show how williams’ characters are seen in the light of such a theoretical framework. keywords: existentialism, existence, choice, alienation