Microglial cells are the resident immune-related glial cells of the central nervous system (CNS) that are crucial for maintaining homeostasis and sensing pathological alterations in the nervous system. To improve our understanding of the biological function of microglia, gene-transfer techniques have been improved and become widely used over the past several years. Here, we describe lentiviral-mediated transduction as a valuable tool for transduction of cultured microglial cells.