This volume constitutes the proceedings of the International Workshop on Advanced Research in Geographic Information Systems, IGIS '94, held in Ascona, Switzerland in February/March 1994. The 28 carefully refereed and revised papers address all current aspects of GIS research and their advanced applications to spatial and environmental data engineering. Among the topics covered are GIS theory, spatial databases, spatial data structures, environmental modelling and control, data modelling, object-orientation, pattern recognition, and optimization. In addition, software and non-commercial as well as commercial GIS are analysed.