We report here the complete nucleotide sequence of the E. coli triose phosphate isomerase gene. The gene encodes a polypeptide of 255 amino acids which is approximately 46% homologous to eukaryotic triose phosphate isomerases, and approximately 38% homologous to the enzyme from a thermophilic bacterium, Bacillus stearothermophilus. The nucleotide sequence is 55% homologous to that of the corresponding gene in the yeast Saccharomyces cerevisiae. To our knowledge, this is the first report of the sequence of a gene coding a glycolytic enzyme from a prokaryotic organism.