The use of the term "infertility" and related terms in reproductive medicine is reviewed. Current terminology is found to be ambiguous, confusing and misleading. We recommend that the fertility investigation report of a couple should consist of statements concerning description, diagnosis and prognosis. The description concerns the duration of non-pregnancy before consulting the clinician. A system for prognostic grading is proposed. The fertility investigation report forms the basis for further action, including the possibility of waiting with treatment in case of almost normal or only slightly reduced fertility. The use of the terms infertility, subfertility and fecundity is not necessary, and it is recommended to avoid them.