NK cells play an important role in the control of viral infections. Cytomegaloviruses have played a big part in the accumulation of current knowledge describing how NK cells recognize and eliminate infected cells. The interference with these functions at multiple levels may not only play a role in the control of primary infections or reactivations but can also impact other arms of the immune system and leave a long-lasting stable imprint on the NK cell population. These imprints may, in turn, modify how we respond to other infections. Understanding these processes will allow us to design better diagnostic approaches and new treatment options through manipulation of our immune responses and the viruses themselves.