Monoclonal antibodies against the epidermal growth factor receptor (anti-egfr) when used in the treatment of metastatic colorectal cancer are associated with improved survival. Patients whose tumours harbor a KRAS mutation in codon 12 or 13 have been shown not to benefit from anti-egfr antibodies. The importance of KRAS mutation status in the management of patients with metastatic colorectal cancer has led to the elaboration of Canadian consensus recommendations on KRAS testing, with the aim of standardizing practice across Canada and reconciling testing access with the clinical demand for testing. The present guidelines were developed at a Canadian consensus meeting held in Montreal in April 2010. The best available evidence and expertise were used to develop recommendations for various aspects of KRAS testing, including indications and timing for testing, sample requirements, recommendations for reporting requirements, and acceptable turnaround times.