In the central nervous system (CNS), astrocytes are the most numerous among glial cells and have diverse physiological functions. These cells also play an important role in many CNS disorders and pathologies. Pituitary adenylate cyclase activating polypeptide (PACAP) is abundantly expressed in the CNS, acting as a neuroprotectant against various neurological threats. PACAP also has been studied as an astrocytic regulator from diversified aspects. PACAP receptor expression has dynamically changed in pathological condition. In this chapter, we summarize the expression and function of PACAP and PACAP receptors in astrocytes and astrocytic tumors, and discuss the role of PACAP in physiological and pathological conditions.