Alzheimer’s disease (AD) is the most common form of dementia, which is progressively affecting elderly people. The dyshomeostasis of biometals and accumulation of toxic metals are usually observed in numerous neurodegenerative diseases including AD. In the central nervous system, metal imbalance–caused neurotoxic activities are usually linked with decreased enzymatic activities, increased aggregation of proteins, and oxidative stress, where a series of processes can result in neurodegeneration and cell death. Even though the relations between neurodegenerative diseases and biometal imbalance are still elusive, there is a growing interest in a group of major endogenous proteins that are associated with the transports of metals. Aberrant expression of these endogenous proteins is associated with the biometal imbalance and AD pathogenesis. Indeed, heavy metals are extremely toxic to the nervous system. Various studies have demonstrated that the toxic effects of heavy metals can result in amyloid beta (Aβ) aggregation, neurofibrillary tangles, and even loss of neurons. In this article, we have focused on the molecular processes through which exposure to biometals and toxic metals can play roles in AD pathogenesis.