Conception of the neutrophils role in the immune system has been changed significantly in the recent time. Many studies prove important and diversified role of this cells in the cancer biology in the last few years. It was shown that their presence in tumor microenvironment has mixed role on cancer growth. This review summaries evidence of neutrophils heterogeneity, plasticity and ability to differentiate into other myeloid types of cells despite formed proinflammatory potential. Prognostic value of tumor-associated neutrophils and high neutrophil level in peripheral blood in patients with different type of malignancies (i.e. renal cell cancer, melanoma, colorectal cancer, hepatocellular cancer, cholangiocarcinoma, glioblastoma, gastrointestinal stromal tumors, gastric cancer, lung cancer, ovarian cancer, head and neck cancer) is discussed. More sophisticated study of existence and functional activity of pro- and antitumor abilities of neutrophils is needed for finding new diagnostic and therapeutic approaches in oncology.