SAGE (Serial Analysis of Gene Expression) is a highly accurate quantitative method for profiling gene expression. We exploited SAGE to study the global gene expression of Magnaporthe grisea during appressorium development induced by cAMP treatment of conidia. More than 3000 tags each were extracted and compared between the cAMP-treated and non-treated (control) conidia. Sequences of the tags for which frequency was considerably more or less in the treatment with cAMP as compared to the control were used for homology search with EST data registered in Genbank and M. grisea genome v.1 (Fungal Genomics Laboratory — North Carolina State University and Whitehead Institute Center for Genome Research). cAMP-induced genes were categorized according to their putative function. Among the cAMP-inducible genes with known functions, those involved in sugar metabolism (respiration) and nucleic acid metabolism were represented as the top two categories. In view of the established EST database and the availability of whole genome sequence in M. grisea, the utility of SAGE for dissecting its pathogenicity will expand in future.