Although the real-life benefits of bevacizumab may differ from clinical trials, observational data are rare. In this cohort study, the effectiveness of bevacizumab in first-line treatment of metastatic colorectal cancer was investigated. Patients initiating bevacizumab between January 2006 and December 2007 were identified in 28 French centres. Outcomes were investigated in the whole cohort and in those with irinotecan-based treatment that was used in the pivotal clinical trial; patients were stratified using inclusion/exclusion criteria of the pivotal clinical trial (PCT) (eligible for the PCT, not eligible or unclassifiable). The Kaplan-Meier method estimated progression-free survival (PFS) and overall survival (OS). A total of 411 patients were included: 57 % male, median age 65.1 years, 78 % Eastern Cooperative Oncology Group performance status ≤1, 88 % irinotecan-based regimen, median duration of bevacizumab use 5.5 months, median OS = 25.3 months (95 % confidence interval, CI [23.3; 27.0]) and median PFS = 10.1 months (95 % CI [9.5; 11.0]). Among the 360 patients who received irinotecan-based chemotherapy, 144 would have been eligible for the PCT, 194 not eligible and 22 unclassifiable. Median OS in those considered eligible was 29.1 (95 % CI [25.4; 33.6]) and in those considered not eligible this was 24.9 months (95 % CI [21.3; 26.9]); median PFS was respectively 11.5 months (95 % CI [10.3; 12.0]) and 9.4 months (95 % CI [8.8; 10.3]). The effectiveness of bevacizumab was found to be similar to that found in other studies including clinical trials which is reassuring.