The field of genetics has seen major advances in recent decades, particularly in research, prevention and diagnosis. One of the most recent developments, the genomic editing technique Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9, has opened the possibility for genetic therapies through genome modification. The technique marks an improvement on previous procedures but poses some serious ethical conflicts. Bioethics is the discipline geared at finding answers to ethical challenges posed by progress in medicine and biology and examining their repercussions for (...) society. It can also offer a conceptualization of these ethical dilemmas. The aim of this paper is to offer a map of the ethical dilemmas associated with this technique by way of a critical analysis of current literature. The main issues can be grouped in four areas: efficacy and security; the types of cells which can be targeted by the technique (somatic, embryonic and gametes); the goal of the therapy; and accessibility and justice. (shrink)