Genomics and the new techniques it embraces, such as cDNA and tissue arrays, comparative genomic hybridization and single nucleotide polymorphism analysis, offer the opportunity to generate massive amounts of data relating to screening, aetiology, diagnosis, prognostication and optimal treatment in colorectal cancer. To make progress, studies must be designed to stringently test these new technologies and compare them to the tried and tested gold standards. This is best done in the form of large randomized controlled trials. Genomics undoubtedly offers the prospect of exciting new developments in the field of colorectal cancer but these should be regarded with caution until they are proved superior to present practices and models.