The development of negative emotions is a problem that manifests in children with tantrums, such as excessive anger. Tantrums can be pathological, so early identification of tantrums can help teachers control them and prevent long-term negative effects. The aim of this study is to identify strategies for dealing with tantrums in children based on the existentialist philosophy of Martin Heidegger, which fosters responsibility within oneself through four aspects. The research method used in this study is qualitative with a case study approach. The data analysis involves triangulation of data acquisition techniques, including observation, interviews, and documents. Observations were conducted on one tantrum-prone child in the second grade. Interviews were conducted with the second-grade teacher and the guidance counselor to determine the strategies used. The results of this study include findings on several ways or strategies employed by the second-grade teacher and the guidance counselor in dealing with tantrum-prone children at school. Firstly, individual support is provided. Secondly, opportunities are given for tantrum-prone children to express their emotions in a conducive environment. Thirdly, fostering self-awareness in children to cultivate tolerance among peers. Fourthly, providing children with opportunities to express the circumstances that make them angry. Fifthly, providing rewards in the form of verbal reinforcement when tantrum-prone children exhibit positive behavior. Sixthly, adopting a humanistic approach, redirecting the child's emotions to a conducive environment, and providing a sense of security by hugging the child when they experience high levels of emotional distress during a tantrum. The conclusion of this study is that strategies for dealing with tantrum-prone children consist of six methods, including individual support, providing opportunities to express emotions and circumstances, fostering self-awareness in children, providing rewards, and adopting a humanistic approach.