Neoplastic diseases are the leading causes of death after cardiovascular diseases in the world. Therefore, an early cancer diagnosis is essential for cancer patients to have the best chances for successful treatment and improve the quality of life. For these purposes, research addressing the possibilities of preventive screening and finding tumor markers is very intensive. In this Thesis, I try to provide an overview of polyamines' chemical structure, metabolism and regulation, and their main biological functions. Next, I review their role as a tumor marker in cancer diagnosis and the limitations we face. I decided polyamines level cannot be implemented for clinical diagnosis of cancer because different polyamines demonstrated different patterns with respect to cancer type and degree of malignancy, elevated levels of polyamines were not specific enough. Further research should focus on finding specific polyamine patterns for different cancer types using not only putrescine, spermidine and spermine levels, but also free and acetylated/deacetylated polyamines. Furthermore, I suggest that polyamines are practical in predicting relapse and effectiveness of treatment because they are involved in cell proliferation and cell death in healthy and cancerous cells. In the end, I provide a review on the main analytical methods for polyamine determination and the future implications of polyamines.