KIBRA is a WW domain-containing protein that can bind to protein kinase Cζ (PKCζ). The SNP of the ninth intron of the KIBRA gene is associated with human episodic memory performance. Protein kinase Mζ (PKMζ), a brain-specific variant of PKCζ, plays important roles in memory formation. Here we examined the interaction of KIBRA and PKMζ in the adult mouse brain. Immunoprecipitation using newly-raised anti-KIBRA antibody revealed the interaction between KIBRA and PKMζ in the brain. KIBRA was co-localized with PKMζ in a single cultured neuron. Distribution analysis by immunohistochemistry and in situ hybridization indicated that KIBRA was highly localized with PKMζ in the hippocampal CA1, CA3, and dentate gyrus. These results suggest that KIBRA functions in memory performance via interaction with PKMζ.