Exposure to an environmental factor (e.g. endocrine disruptor) during embryonic gonadal sex determination appears to be epigenetically reprogram the male germ-line and subsequently promote transgenerational adult-onset disease. Disease phenotypes resulting from this epigenetic phenomenon include testis abnormalities, prostate disease, kidney disease, tumor development, and immune abnormalities. The epigenetic mechanism is hypothesized to involve the induction of new imprinted-like DNA sequences in the germ-line to transgenerationally transmit disease phenotypes. This epigenetic transgenerational disease mechanism provides a unique perspective from which to view adult onset disease and ultimately offers new insights into novel diagnostic and therapeutic strategies.