Clinical information regarding 3 patients diagnosed with acute thallium poisoning was collected and retrospectively analyzed. All 3 patients presented with severe burning pain in the lower limbs and the abdomen. Diffuse alopecia, hepatic dysfunction and Mees’ lines in the digits of each limb were observed between 2 and 3 weeks after onset. A physical examination demonstrated paresthesia of all 4 limbs, but normal deep tendon reflexes. Blood and urine thallium concentrations were significantly elevated. Treatment was initiated using hemoperfusion, hemodialysis, potassium supplementation, oral laxatives and B complex supplementation. Clinical symptoms improved as blood and urine thallium concentrations decreased, although a residual sensory neuropathy remained. This study demonstrated that the primary clinical manifestations of acute thallium poisoning include gastrointestinal symptoms, polyneuropathy and dermatological changes. Hemoperfusion and hemodialysis may be effective treatments for acute thallium poisoning.