The problem of identity theft is current all over the world. Nowadays we can even observe a tendency for an increasing occurrence of this kind of behaviour. The rapid development of new communication tools and the Internet has made it easier to commit a crime of identity theft than ever before. Despite this seemingly obvious trend in the world, in Poland since 2011, when this phenomenon was criminalized, convictions for identity theft are still one of the rarest situations. Identity theft as a proportion of general identified offences in 2017, according to Police statistics, was only .30%. The paper will present selected legal aspects of identity theft from the Polish Criminal Code, as well as criminological analysis of the phenomenon in Poland. The results of research on identity theft conducted in the District Court in Białystok on court files that ended in a final court judgment covering the years 2011–2016 will also be presented. In the course of the research process, seven cases were found and examined. The analysis was enabled by using a questionnaire, which included forty-nine questions grouped into categories, i.e. characteristics of the perpetrator of the crime, characteristics of the victim, description of the committed act, as well as the course of the pre-trial and judicial proceedings. In the paper, an attempt will be made to find an answer to the question of why the dark number of identity theft crimes in Poland is still great, and this will help characterize identity theft in the area of Białystok.