This thesis aims to discuss the indeterminacy of law through the lenses of the legal realism movement and the thoughts of H. L. A. Hart. The insights and works of Holmes and Pound opened the way for American legal realism and were used as building blocks for the work of legal realists such as Jerome Frank and Karl Llwellyn, among others. One of the best known points of legal realism is that judges first arrive at their decision through non-legal means and then seek, in the legal material, the basis for justifying their decisions. According to the legal realists the legal material can justify just about any decision arrived at through non-legal means. Jerome Frank placed a high degree of subjectivism in the legal decisions, going as far as explaining how judges decide based on what they had for breakfast. Hart, as the legal realists, also defends the indeterminacy of law. However, according to him law’s indeterminacy is due to the open texture of language. The present work will investigate the position of the realists and H.L. A. Hart about the indeterminacy of law. Even though they converge on the indeterminacy thesis, they disagree about its root causes.