What is happening to the human male?Something strange is happening to the human male. The incidence of testicular cancer is increasing dramatically in all the advanced economies on Earth, male infertility has reached epidemic proportions, sperm counts are declining at an alarming rate and paternal impacts on offspring health are becoming increasingly apparent. Notably, the incidence of testicular cancer shows a strong correlation with socio-economic development such that, globally, it has become the major cancer afflicting young males. In parallel with the increased incidence of testicular cancer, sperm counts have been falling across the globe. The reason for this decline in semen quality is uncertain at the present time but it may be an indirect reflection of falling testosterone levels, possibly fuelled by oestogenic factors in the environments we inhabit, the food we eat, the water we drink, the drugs we take, the lifestyles we adopt and the metabolic patterns we experience in affluent society. The resultant oestrogenic load may impact male reproductive health at any point in sexual development from fetal life to adulthood. Controlling the exposures responsible for these impacts on male reproduction is essential because, if current trends continue unabated, it will have as major impact on the future of our species.