Abstract. The biomedical literature grows at a tremendous rate, so that finding the relevant literature is becoming more and more difficult. To address this problem we introduce ontology-based literature search, which structures search results thorugh the categories of an ontology. We develop and implement GoPubMed, which submits keywords to PubMed, extracts GeneOntology-terms from ieved abstracts, and presents the relevant sub-ontology for browsing. For GoPubMed we develop a novel term extraction algorithm and evaluate its performance. GoPubMed is available at www.gopubmed.org