A Preliminary Report on Answering Complex Queries related to Drug Discovery using Answer Set Programming Olivier Bodenreider National Library of Medicine National Institutes of Health, USA Zeynep H. Coban Department of Biostatistics Harvard School of Public Health, USA Mahir C. Doganay Department of Mathematics and Computing Science University of Groningen, The Netherlands Esra Erdem Faculty of Engineering and Natural Sciences Sabanci University, Turkey Hilal Kosucu Department of Computer Science University of Toronto, Canada We introduce a new method for integrating relevant parts of knowledge extracted from biomedical ontologies and answering complex queries related to drug safety and discovery, using Semantic Web technologies and answer set programming. The applicability of this method is illustrated in detail on some parts of existing biomedical ontologies. Its effectiveness is demonstrated by computing an answer to a real-world biomedical query that requires the integration of NCBI Entrez Gene and the Gene Ontology.