We have studied the efficacy of bevacizumab in colorectal cancer with unresectable metastasis patients who had undergone resection of primary tumor. The patients with unresectable metastasis during diagnosis who had undergone resection of primary tumor without chemotherapy and the patients without resection of primary tumor were included. Among patients who had met the inclusion criteria, 46 patients with resection of primary tumor and 47 without resection of primary tumor were included in the study. A total of 93 unresectable metastatic colorectal cancer patients were included in the study. Median PFS was 9 months (95 % CI 7.37-10.62) in patients with resected primary tumor and bevacizumab containing first-line chemotherapy combination. Median PFS was 10 months (95 % CI 8.06-11.93) in patients without bevacizumab (P = 0.66) Median OS was 25 months (95 % CI 17.92-32.07) in patients with resected primary tumor and bevacizumab containing first-line chemotherapy combination. Median OS was 16 months (95 % CI 9.71-22.28) in patients without bevacizumab (P = 0.36) Median OS was 16 months (95 % CI 13.06-8.939) in patients without resected primary tumor and bevacizumab containing first-line chemotherapy combination. Median OS was 9 months (95 % CI 1.48-16.51) in patients without bevacizumab (P = 0.012). Bevacizumab seems ineffective in mCRC patients with resected primary tumor. An increase in number of retrospective literature data and randomized, prospective studies is required about this subject.