The progression of biotechnology and genetic engineering to produce transgenic animals by familiarizing the foreign DNA into the germline of an animal has elevated the potential of biological research to an unprecedented level. This technology not only beneficial in human welfare, society, and the environment but also harmful. At present, many transgenic species (goats, chickens, pigs, cows, mice, rabbits, sheep, etc.) are considered for research applications as well as latent profitable pharmaceutical productively. Transgenic animals are applied as the different models for the experiment of different diseases including HIV/AIDS, Alzheimer’s, Cardiovascular, and Diabetes Mellitus, Angiogenesis, and Cancer disease. The main disadvantages of transgenic animals are mutagenesis and function disorders, ecological problems, antibiotic resistance, and population of clones.