The widespread entry of nanomaterials into manifold life fields posed serious concerns on environmental health and safety issues. Potential adverse effects of nanoparticles (NPs) are continuously faced using in vitro cell systems and by mean of cell and molecular biology tools, several mechanisms have been found beyond their toxicity. The evaluation of the in vivo possible consequences derived from exposure of living organisms to NPs is instead more complex but compulsory in view of their application for diagnosis or therapeutic purposes. Here the effects of NP-induced genetic alteration on the progeny of treated animals will be treated, considering selected species from invertebrate and vertebrates as examples of transgenerational transmission of NP toxicity. The effects on reproductive capability, fertility and embryogenesis observed in different animal species upon treatment with different materials will provide an overview of the current knowledge on the heritable feature of nanotoxicity.