Globally, neurodegenerative diseases account for 4% and 5% of deaths and disabilities, respectively, among non-communicable diseases. Because of the lack of effective treatment in most cases, the consequences of neurodegenerative diseases, once diagnosed, can be extremely serious. Neurodegenerative diseases take many forms, some of which are of occupational origin. Motor neuron disease (MND) is a progressive degenerative disease that selectively attacks motor neurons in the spinal cord, brainstem, and cortex. Although most cases of MND are spontaneous, recent studies on the etiology of MND suggest that, in addition to genetic factors, occupational exposures and environmental factors (agricultural chemicals, welding, various metals, organic solvents, formaldehyde, etc.) are suspected to increase the risk of MND, although the evidence is inconsistent. A recent series of MND cases suggests that MND is associated with exposure to methyl bromide. Other putative risk factors include military service, history of head trauma (including sports injuries), etc. Parkinson’s disease (PD) is a neurodegenerative disorder that causes a variety of progressive motor or non-motor symptoms and increases the risk of disability. Although the cause is unknown, the relationship between PD and occupational disease has been studied in depth by researchers. The only known etiology, at this time, may be related to manganese exposure, although manganese toxicity has some unique behavioral or pathological features compared to typical Parkinson’s disease. Also certain pesticides such as paraquat and rotenone are strongly suggested to increase the risk of PD. Other occupational exposures, such as organic solvents and wood preservatives, are also suspected to have a correlation with PD, but the evidence lacks consistency. Dementia is a collective term for a number of symptoms including memory impairment, mood changes, and communication problems. Alzheimer’s disease (AD) is one of the most common forms, and it is projected that by 2050, there may be 1 in 85 people with dementia. No causal relationship has been shown between occupational exposure and the development of dementia, but factors such as pesticides, herbicides, and metal exposure (aluminum, zinc, copper, and lead) remain associated with dementia. MS is a neuroinflammatory disease, and although there is less evidence of an association with occupational exposure, there is still evidence suggesting that MS is associated with solvent exposure. In addition to these 4 major categories of neurodegenerative diseases, other clinical or subclinical neuropathies may also result from occupational causes. With respect to cancer, respiratory diseases, and other noncommunicable diseases, numerous cohort and case-control studies have been conducted over the past 40 years and have found that at least 4% (and up to 10%) of cancers are due to occupational causes. It is not surprising that occupational exposures are found to account for a similar or higher proportion of neurodegenerative disease etiologies, even if they are eventually found. Globally, neurodegenerative diseases account for 4% and 5% of deaths and disabilities, respectively, among noncommunicable diseases. Because of the lack of effective treatment in most cases, the consequences of neurodegenerative diseases, once diagnosed, are extremely serious. Neurodegenerative diseases take many forms, some of which are of occupational origin. Motor neuron disease (MND) is a progressive degenerative disease that selectively attacks motor neurons in the spinal cord, brainstem, and cortex. Although most cases of MND are spontaneous, recent studies on the etiology of MND suggest that, in addition to genetic factors, occupational exposures and environmental factors (agricultural chemicals, welding, various metals, organic solvents, formaldehyde, etc.) are suspected to increase the risk of MND, although the evidence is inconsistent. A recent series of MND cases suggests that MND is associated with exposure to methyl bromide. Other putative risk factors include military service, history of head trauma (including sports injuries), etc. Parkinson’s disease (PD) is a neurodegenerative disorder that causes a variety of progressive motor or non-motor symptoms and increases the risk of disability. Although the cause is unknown, the relationship between PD and occupational disease has been studied in depth by researchers. The only known etiology, at this time, may be related to manganese exposure, although manganese toxicity has some unique behavioral or pathological features compared to typical Parkinson’s disease. Also certain pesticides such as paraquat and rotenone are strongly suggested to increase the risk of PD. Other occupational exposures, such as organic solvents and wood preservatives, are also suspected. If this turns out to be true, occupational neurological diseases will become a major public health problem. Therefore, a concerted effort is needed in the coming decades to explore the correlation between occupational causes and neurological disorders more deeply and extensively.