PLC-η2 is a recently discovered member of the phosphatdylinositol-specific phospholipase C (PLC) family. These enzymes are vital for inositol lipid signaling by facilitating intracellular Ca2+ release and protein kinase C activation. PLC-η2 is particularly sensitive to the intracellular calcium concentration and is thought, due to its expression profile in the hippocampus and cerebral cortex, to function in learning and memory. PLC-η2 contains a number of conserved domains including, pleckstrin homology (PH), EF hand, X and Y catalytic and C2 domains. We investigated the role of the PH and C2 domains in regulating PLC-η2 function by producing a PH domain lacking protein and generating point mutations in the C2 domain. We then measured activity using a 3H-inositol phosphate assay and intracellular localization by confocal microscopy with GFP-tagged PLC-η2 constructs in COS-7 cells. We demonstrate that the PH domain is important for membrane localization and that the C2 domain plays an important role in controlling PLC-η2 activity.