This paper introduces a new type of Self-Organizing Map (SOM) for Text Categorization and Semantic Browsing. We propose a “hyperbolic SOM” (HSOM) based on a regular tesselation of the hyperbolic plane, which is a non-euclidean space characterized by constant negative gaussian curvature. This approach is motivated by the observation that hyperbolic spaces possess a geometry where the size of a neighborhood around a point increases exponentially and therefore provides more freedom to map a complex information space such as language into spatial relations. These theoretical findings are supported by our experiments, which show that hyperbolic SOMs can successfully be applied to text categorization and yield results comparable to other state-of-the-art methods. Furthermore we demonstrate that the HSOM is able to map large text collections in a semantically meaningful way and therefore allows a “semantic browsing” of text databases.