Background: Failure to get pregnant after 12 months of unprotected sexual intercourse is described as infertility. Infertility affects 15 percent of the world's population, and in 50 percent of cases, a male component, such as poor sperm quality, is involved. Male infertility is now a mystery, with many theories as to what causes it. Semen analysis abnormality is usually invariably a sign of male infertility, but other male variables may still play a role even if the semen analysis is normal. Infertility in males can be caused by varicocele, genital infections, endocrine disruptors, genetic and immunological and systemic illnesses as well as environmental causes. Objective: To discuss overview of male infertility causes, risk factors, diagnosis with special care of semen analysis. Methods: PubMed, Google scholar and Science direct were searched using the following keywords: Male Infertility, Semen analysis and Risk factors of infertility. The authors also screened references from the relevant literature, including all the identified studies and reviews, only the most recent or complete study was included between May 2012 and July 2021. Documents in a language apart from English have been excluded as sources for interpretation was not found. Papers apart from main scientific studies had been excluded: documents unavailable as total written text, conversation, conference abstract papers and dissertations. Conclusion: Male infertility accounts for over 20% of all causes of infertility in couples, and semen analysis is the only test that can reliably diagnose 9 out of 10 men who have a real issue with male infertility, with a sensitivity of 89.6%.