The colorectal cancer treatment has significantly changed in last few years. Use of new drugs such as oxaliplatin, irinotecan, or capecitabine improved long term survival of patient with this disease. Research of biologic and genetic behavior of CRC has brought new ways in therapy called "biologic therapy". Standard today's treatment consist of three drugs: bevacizumab (antiVEGF antibody), cetuximab and panitumimab (anti EGFR antibodies). Biology therapy should be used simultaneously with chemotherapy only and after genetic examination of the cancer (K ras mutation). For patients with stage III the adjuvant therapy with combination of FOLFOX (oxaliplatin, fluorouracil, and leukovorin) is recommended to reduce the probability of recurrence and improve survival. In stage IIB there is a clear need to determine further risks which classify the high risk patients who should be enrolled in adjuvant chemotherapy. In palliative treatment of colorectal cancer there are several chemotherapy combinations (FUFA, FOLFOX, FOLFIRI, XELOX, XELIRI) used with biologic therapy. International recommendation for the biologic therapy is in the first line treatment bevacizumab and cetuximab or panitumumab in the second line is recommended. The new discoveries in biology of colorectal cancer show the need of tailoring.