The ability of an environmental exposure (i.e. endocrine disruptor) during sex determination to reprogramme the male germline and promote an epigenetic transgenerational disease phenotype suggests that environmental factors and compounds may permanently alter the germline epigenome. This epigenetic transgenerational phenomenon will be discussed with respect to adult-onset germline disease (e.g. testicular cancer). A thorough literature review is not provided, rather a perspective is provided on how this epigenetic transgenerational toxicology should be considered in germ cell disease and testicular cancer.