The common marmoset (Callithrix jacchus) is a small New World non-human primate indigenous to northeastern Brazil. This species has been attracting the attention of biomedical researchers and neuroscientists for its ease of handling and colony maintenance, unique behavioral characteristics, and several human-like traits, such as enriched social vocal communication and strong relationships between parents and offspring. Its high reproductive efficiency makes it particularly amenable for use in the development of transgenic and genome editing technologies in a non-human primate model. Our group has recently generated transgenic marmosets with germ line transmission, opening new avenues in primate research. In this chapter, we describe recent advances in neuroscience and disease research using common marmosets, and we outline potential uses of genome editing in non-human primates toward the development of knock-in/knock-out marmosets.