Colorectal cancer has an important place in worldwide death from cancer causes. Angiogenesis, in which angiogenic factors such as VEGF and basic FGF have a key role, is an important factor in patient survival with respect to progression and metastatic spreading in colorectal cancer. In this study, we aimed to determine whether serum VEGF and bFGF pre- and post-treatment serum levels are decisive in evaluating response to treatment and progression in metastatic colorectal cancer (mCRC) patients treated with FOLFIRI-bevacizumab. In 33 mCRC patients serum VEGF and bFGF levels were monitored at the beginning of treatment and until progression during FOLFIFilbevacizumab. In our study serum VEGF and bFGF levels were significantly higher than the healthy controls (p < 0.001). We found that the patients with pre-treatment high serum bFGF levels have significantly short Progression free survival. In patients with pre-treatment low serum VEGF value (<147.79 pg/ml) had significantly longer overall survival (27.93 vs 23.27 months p:0.026) in metastatic rectum cancer. In multivariate analysis were found to be prognostic factors VEGF levels, response to treatment and side of the tumor for PFS and VEGF levels, response to treatment and whether to be operated of tumor for overall survival. Conclusions: Serum VEGF level was detected to be one of the factors that determine PFS and overall survival in mCRC. Pre-treatment serum bFGF levels were determined PFS and monitorization of serum bFGF during treatment was found to be related to response to treatment. Although there was no statistical significance, in mCRC patients, whose pre-treatment serum VEGF were high, PFS was longer with bevacizumab treatment. The importance of pretreatment high serum VEGF level to select for treatment of bevacizumab will be planned in metastatic CRC requires to be confirmed in comprehensive, prospective studies.