Primary human diploid fibroblasts are used routinely to study host/pathogen interactions of human cytomegalovirus (HCMV). Fibroblasts' ease of culture and tremendous permissiveness for infection allow the study of all facets of infection, an abbreviated list of which includes ligand/receptor interactions, activation of cell signaling responses, and dysregulation of the cell cycle and DNA repair processes. Another advantage to fibroblasts' permissiveness for HCMV is the capability to grow high titer stocks of virus in them. This chapter will discuss the production of viral stocks of HCMV in primary human fibroblasts, commencing with culturing and infection of cells and continuing through harvest, titration (determining the infectious capacity of a particular virus preparation), and storage of viral stocks for use in downstream experiments.