Pathological hyperphosphorylation of tau and subsequent aggregation to form neurofibrillary tangles (NFTs) is closely related to progression of neurodegenerative diseases such as Alzheimer's disease (AD) and progressive supranuclear palsy. A recent study showed that MK-8719 (6) is a selective and potent small molecule inhibitor of human O-GlcNAcase (hOGA). The pharmacological inhibition of OGA, the sole enzyme involved in removal of a sugar moiety (O-GlcNAc residue) from tau, increases global O-GlcNAc levels within the brain and reduces tau phosphorylation. The OGA inhibitor slows neurodegeneration and improves cognitive function in AD and related tauopathies. Here, we discuss the findings of that study and the development of OGA inhibitors as novel therapeutic strategy for treatment of age-related memory impairment in neurodegenerative diseases.