This paper investigates Heidegger’s concept of anxiety in Being and Time, and re-reads a certain mode of Heideggerian Angst in Franz Kafka’s The Castle and Samuel Beckett’s Waiting for Godot. In Heidegger’s existential-ontological point of view, through anxiety Dasein [human being] who is in an uncertain existence takes issue with its Being [Sein] and chooses its mode of Being, i.e. inauthenticity or authenticity. This anxiety breaks with the meaningless games of Dasein, and urges Dasein to reach authentic possibilities of its Being. Despite the uncertainty of Klamm’s existence in The Castle, protagonist K visits the castle to see him; Klamm is nowhere to be found, and K is suddenly seized with the anxiety that he won’t be able to meet Klamm while having fun with Frida, Klamm’s mistress, and his two assistants. Applying Heidegger’s concept of anxiety to Kafka’s text, this paper asserts that it is anxiety that causes K to awaken his Being. Likewise, despite the uncertainty of Godot’s existence in Waiting for Godot, Gogo and Didi keep waiting for this absent character; as with Kafka’s text, he too is absent. Gogo and Didi fall into a state of anxiety that they won’t be able to meet Godot while playing meaningless games in order to forget the pain of their Being in trapped with a desperate existential mode. This paper illumines how the anxiety of Gogo and Didi can also be read as Heideggerian, and it is this Angst that causes these characters to reach their own authentic possibility of Being.