Phosphorylation of signal transducers and activators of transcription (STATs) indicates their involvement in active signaling. Here we describe immunohistochemical staining procedures for detection and identification of the cellular localization of phospho-STAT2 in the central nervous system (CNS) of mice. The procedures include single and dual/triple labeling immunostaining of phospho-STAT2 in the hippocampus of mice following entorhinal cortex lesion.