The metabolic network of *Saccharomyces cerevisiae* was reconstructed using genomic, biochemical, and physiological information. The network includes 708 structural open reading frames (ORFs) and 1035 metabolic reactions, with 140 additional reactions based on biochemical evidence, resulting in a total of 1175 metabolic reactions and 584 metabolites. The network accounts for ~16% of all characterized ORFs in *S. cerevisiae*. The reconstructed network was used to calculate and compare the metabolic capabilities of *S. cerevisiae* with those of *Escherichia coli*. This is the first comprehensive genome-scale metabolic network for a eukaryotic organism, providing a foundation for in silico analysis of phenotypic functions. The reconstruction process involved integrating information from various databases and literature sources, considering compartmentation, transport steps, and cofactor requirements. The network was validated by comparing simulated results with experimental data from anaerobic and aerobic chemostat cultivation. The reconstructed network includes 26 protein complexes and 193 ORFs coding for isoenzymes, and it shows that *S. cerevisiae* is more efficient in producing precursor metabolites and amino acids compared to *E. coli*. The network can be used to study metabolic engineering strategies and systems biology applications.The metabolic network of *Saccharomyces cerevisiae* was reconstructed using genomic, biochemical, and physiological information. The network includes 708 structural open reading frames (ORFs) and 1035 metabolic reactions, with 140 additional reactions based on biochemical evidence, resulting in a total of 1175 metabolic reactions and 584 metabolites. The network accounts for ~16% of all characterized ORFs in *S. cerevisiae*. The reconstructed network was used to calculate and compare the metabolic capabilities of *S. cerevisiae* with those of *Escherichia coli*. This is the first comprehensive genome-scale metabolic network for a eukaryotic organism, providing a foundation for in silico analysis of phenotypic functions. The reconstruction process involved integrating information from various databases and literature sources, considering compartmentation, transport steps, and cofactor requirements. The network was validated by comparing simulated results with experimental data from anaerobic and aerobic chemostat cultivation. The reconstructed network includes 26 protein complexes and 193 ORFs coding for isoenzymes, and it shows that *S. cerevisiae* is more efficient in producing precursor metabolites and amino acids compared to *E. coli*. The network can be used to study metabolic engineering strategies and systems biology applications.