In this impressive volume, the editors have pulled together an international cast of distinguished authors, who present a detailed account of sperm function testing in terms of rationale, methodologies and clinical significance. In this introduction, my intention is to give a historical perspective on the evolution of these techniques and a view of where this field will head in the future. For what it is worth, I should also mention that these reflections are presented from the standpoint of someone who has spent the best part of half-a-century considering how we can reliably and effectively monitor the functional quality of human spermatozoa.