Alzheimer's disease (AD), which accounts for three fourth of all cases of dementia, is a major public health problem in modern society and, yet, there is no effective treatment available that can prevent or inhibit this chronic progressive neurodegenerative disease. A major current drug target is intraneuronal abnormally hyperphosphorylated microtubule-associated protein tau which is a histopathological hallmark of this disease and of a family of neurodegenerative diseases called tauopathies. Areas covered: In this review, the authors discuss a growing number of studies that describe the nature and mechanism of tau pathology and various drug discovery options and most recent developments in tau-based therapeutics. PubMed was used to obtain relevant literature while clinicaltrials.gov site and Google search were employed to obtain the latest information on tau based AD clinical trials. Expert opinion: In authors' opinion, loss of neuronal connectivity leads to the hyperphosphorylation of tau and is thus a key therapeutic target. Rescue of neuronal connectivity loss and hyperphosphorylation of tau are most promising approaches. Consequently, tau immunotherapy has a high therapeutic potential.