Microsurgical epididymal sperm aspiration (MESA) is a novel technique that makes the retrieval of sperm from the obstructed epididymis possible. When combined with advanced reproductive measures, such as in vitro fertilization, pregnancies can be achieved. This raises new questions about the function of the epididymis, once thought to be indispensible for the full maturation of human sperm. Continued research will hopefully lead to even higher conception rates using epididymal sperm while also helping to provide a fuller understanding of the interaction between the epididymis and the spermatozoa that traverse it.