Several family members of Krüppel-like factors (KLFs) are found in lymphocytes, and their expression is tightly regulated during development and differentiation. The related factors KLF2 and KLF4 have been suggested to promote lymphocyte quiescence by inducing withdrawal of cells from the cell cycle. Although the physiological role of KLF2 in cell cycle control in lymphocytes is currently unclear, it is potentially due to redundancy between related KLFs. On the other hand, there is growing evidence that individual KLFs regulate migration of lymphocytes (and other cells) during normal homeostasis of the immune system and in inflammatory situations. In addition to KLF2 and KLF4, the roles of KLF10 and KL13 in lymphocytes are briefly discussed.