Although acute thallium intoxication may induce various clinical features, it mainly results in dermatological and neurological deficits. Skin changes include a peculiar deposit of a dark pigment in the hair roots several days after intoxication, followed by hair loss 10 days later and complete alopecia 3 to 4 weeks later. In addition, the impairment of sweat and sebaceous glands and hyperkeratosis are also noted. Typical Mees’ lines appear in the fingernails and toenails 2-3 months later. Dermatological deficits may subside 3 months later. The neurological deficits of acute thallium intoxication include severe painful neuropathy and a debilitating encephalopathy. The neuropathy is usually painful, and excruciating pain is the most prominent symptom. It usually appears in the following day after acute thallium intoxication and may persist for a long time. Axonal damage may involve both the large and small fibers. Free nerve endings of the skin are severely damaged and the recovery is partial. The central nervous system (CNS) is also severely involved. The term “encephalopathia thallica” encompasses a range of CNS damages, including memory deficits and cognitive impairment. Brain magnetic resonance images show lesions in the corpus striatum. Functional neuroimage such as by fluorodeoxyglucose positron emission tomography also shows a decreased uptake in the cingulate gyrus and diffuse cortical area. No specific antidote is available for thallium intoxication. However, gastric lavage, activated charcoal, hemoperfusion and Prussian blue may be helpful to prevent further damages.