Chickens have proven to be useful organisms for transgenic research. This work provides enormous benefits in advancing animal biotechnology and aids in the development of unique technologies for bioreactor production and experimental model development. The various advantages of chicken transgenesis are derived from the genetic and physiological characteristics of this organism, although several physiological properties have impeded the development of an efficient transgenic system. We have developed embryo-mediated and testis-mediated transgenic systems using chicken primordial germ cells (PGCs) from embryos and testicular cells from adult males. These methods are efficient and involve minimal technical effort. Here, we review previous transgenic research using PGCs and testicular cells from chickens. Furthermore, we have summarized the development of the chicken model system in biomedical science and biotechnology and our recent achievements in this field.