Since several decades numerous experimental and epidemiological experiments tend to establish that in humans the semen volume declines with progression of age. This literature review is intended to report the association between male age and semen volume. Review of English language-published research over the last 33 years, from January 1, 1980, up to December 31, 2013, has been conveniently constructed using MEDLINE database. Studies with inadequate numbers of subjects and case reports were excluded. Among the methodologically stronger studies, declines in semen volume of 3%-22% were likely when comparing 30-year-old men to 50-year-old men. The report suggests that increased male age is associated with a decline in semen volume, i.e. there has been a genuine diminution in semen volume over the past 33 years. As male fertility is to some extent correlated with semen volume the results may reflect an overall reduction in male fertility. © 2015 Hainan Medical College.