This paper gives an overview of the existing research topics in the field of SME digitalization. Digitalization commonly causes severe changes in both, organizational structures, business models and the IT landscape of an enterprise, i.e., there is a need for business and IT-alignment. By means of a literature analysis and a subsequent systematic mapping study the paper examines on which areas current research work in the field is focused and where potential research gaps exist. The literature analysis has its focus on already existing literature analyses in order to get a comprehensive overview. All identified papers are subsequently classified and visually represented in a diagram. The classification is done in two dimensions. Dimension 1 shows to which step of the digital transformation process the papers refer, dimension 2 refers to the success factors of the digital transformation. The result shows that the focus of recent research mainly was on the analysis of the current situation in companies and that the other steps of the digital transformation are largely ignored. The paper also concludes that there is no step-by-step guide for SMEs that shows how to go through the digital transformation.