Proper names are something we face every day without even wondering what they realy mean. Thinking about them, we come to the realization that with each name we associate some beautiful or ugly memories, good or bad characteristics. Proper names are given to specific person or thing and they should not be changed, adapted or translated into other languages. Unlike proper names in real life and government and personal documents, names in literary works have different connotations and therefor are more susceptible to change and translation. We see it mostly in translations of the Bible, children's literature and science fiction. In the translations of the Bible, proper names are adapted into the languages they are translated to in order to bring this religious text and teaching closer to the readers. When translating children's literature, names are translated so that the child reader would pay more attention to the meaning the text sends and to keep the context of the story more closer to target language. This paper describes, more closely, translation of proper names into the Czech and Croatian languages of the sci-fi book Harry Potter and Philosopher's Stone. Based on this book, we can see how translators cope with translations of proper names. Translators have a difficult task of deciding which names to translate, why, in what way, and find an adequate equivalent in the target language. They have to make sure that they don't disturb the meaning and essence of the original text.