The main aim of the article is to present Melchior Wańkowicz’s theory of reportage, including related techniques, such as: mosaic-technique, crossing the line between non-fiction and fiction, stylistic aspects. The analysis emphasizes creative self-awareness of the writer, shows the process of forming and putting theory into practice. The article indicates an unbreakable link between theory and the creative process of Melchior Wańkowicz. The paper concludes with a presentation of the critic’s reception of author’s work.