In this study nine cases of thallium poisoning in a series of homicidal poisoning were analyzed in order to provide more information concing thallium poisoning. It was found that the most common clinical feature of thallium poisoning was peripheral neuropathy and paraesthesia was more common than amyasthenia. Understanding of these clinical characteristics of thallium poisoning was helpful to early identification and differential diagnosis. Since the early administration of Prussian Blue, as a specific antidote for thallium poisoning, can substantially improve the prognosis, it is of great importance to establish a correct and early diagnosis.