We present an approach combining bioinformatics prediction with experimental microarray validation to identify new cell cycle-regulated genes in Saccharomyces cerevisiae. We identify in the order of 100 new cell cycle-regulated genes and show by independent data that these genes in general tend to be more weakly expressed than the genes identified hitherto. Among the genes not previously suggested to be periodically expressed we find genes linked to DNA repair, cell size monitoring and transcriptional control, as well as a number of genes of unknown function. Several of the gene products are believed to be phosphorylated by Cdc28. For many of these new genes, homologues exist in Schizosaccharomyces pombe and Homo sapiens for which the expression also varies with cell cycle progression. Copyright © 2005 John Wiley & Sons, Ltd.