Our understanding of the human pathogenic fungus Aspergillus fumigatus has recently benefitted from much work at the genomics level, including genome sequencing and comparative genome analyses. The next stage in this process is to develop a higher-level appreciation of the organism's biology and to this end the Pathway Tools software has been used to map the metabolic pathways of A. fumigatus Af293. The resulting web-based resource shows 242 pathways which can be viewed at a variety of resolutions. Some pathways have been manually curated (e.g., ergosterol biosynthesis, 4-hydroxymandelate degradation, fatty acid β-oxidation, fatty acid ω-oxidation, the glyoxylate cycle, palmitate biosynthesis, pyridoxal 5'-phosphate salvage, sphingolipid metabolism, ubiquinone biosynthesis and very long chain fatty acid biosynthesis) while others can be used as a starting point for more detailed research. The pathways can be viewed via the Scientific Information:Genomes section of the Aspergillus website ( www.aspergillus.org.uk ).