For many years gene therapy has been focused on fighting cancer and devising new ways and approaches for treatment. It is based on gene or gene segments transfer with the aim of modifying cancer cells. Progress has been made by development of viral and non-viral vectors as gene carriers, and various mechanisms of action such as oncogene silencing, replacement of tumor suppressor genes, gene repair and immunotherapy. One of the advantages of gene therapy is selective targeting and elimination of tumor cells, thus achieving very little toxicity to the surrounding tissues and organs. There are still problems with the construction of an ideal vector that would allow repair of gene mutations and have the least possible toxicity for the patient. Currently, nanotechnology plays an important role in the construction of new and effective non-viral vectors in gene therapy. There are large number of clinical trials with only few successful results and a small number of approved and available therapies. Activating the immune response against tumor tissue (immunotherapy) is one of the methods with promising results. Although it has numerous advantages, the possibilities of gene therapy are limited due to toxicity, efficiency and availability for commercial use.