The aim of this article is to present the phenomenon of stalkerism (a kind of illegal tourism) in the Chernobyl Exclusion Zone. The article investigates the specificity of the stalker experience through the concept of transgression (Kozielecki 2007). The article broadens the perspective on the tourism experience by using a psychological concept that has not so far been widely used in tourism studies, even though it refers to classic ideas (liminality, rites of passage, transformation). The genesis and specificity of the phenomenon of stalkerism in the context of the development of organized tourism in the Zone are presented. Then the transgressions of stalkers during exploration of the Zone are described. Lastly, the article shows how stalkerism contributes to the transformation of tourism and the development of the Zone’s heritage.