Transgenic mouse technology is a powerful method for studying gene function and creating animal models of human diseases. Currently, the most widely used method for generating transgenic mice is the pronuclear microinjection method. In this method, a transgenic DNA construct is physically microinjected into the pronucleus of a fertilized egg. The injected embryos are subsequently transferred into the oviducts of pseudopregnant surrogate mothers. A portion of the mice born to these surrogate mothers will harbor the injected foreign gene in their genomes. These procedures are technically challenging for most biomedical researchers. Inappropriate experimental procedures or suboptimal equipment setup can substantially reduce the efficiency of transgenic mouse production. In this chapter, we describe in detail our microinjection setup as well as our standard microinjection and oviduct transfer procedures.