Epidemiological data indicate that infertility is a problem of global proportions, affecting one- fifth of couples trying to conceive worldwide (60-80 mln). According to the trends observed, the problem is predicted to increase by another two million cases annually. In Poland, infertility-related issues are found in about 19% of couples, including 4% with infertility and 15% with limited fertility. Inability to conceive occurs equally in men and women (50%), irrespective of the direct cause. Although it is generally thought that reproductive issues concern women, infertility affects men and women equally. This study is an attempted to systematize knowledge about the role of the male factor in infertility, particularly current knowledge concerning the environmental factors of infertility. For this purpose, the Medline and CINAHL databases and the Cochrane Library was searched for articles published in English during the last 10 years, using the following keywords: infertility, male factor, semen examination and environmental factor of infertility.