Background: Randomised controlled trials (RCTs) of anti-EGFR monoclonal antibodies (MAb) in patients with advanced colorectal cancer (aCRC) have reported conflicting results. Methods: A systematic review of RCTs comparing standard treatments ± anti-EGFR MAbs was conducted. Hazard ratios (HR) for progression-free (PFS) and overall survival (OS) were derived for patients with wild-type (WT) and mutant KRAS. Prespecified analyses were conducted for line of treatment, MAb used, chemotherapy regimen, and choice of fluouropyrimidine. Trials using bevacizumab on both arms were included in a sensitivity analysis. Results: Fourteen eligible RCTs were identified, with results by KRAS status available for ten RCTs. For third line treatment, the effect of anti-EGFR MAbs depended on KRAS status (interaction p