Dynamic phenomena are key concerns of IS researchers. However, the methodological approaches usually selected to investigate IS phenomena often rely on variance theory. Underlying factor models represent a rather static approach to the phenomenon by focusing on independent and dependent variables and explaining the degree of the relationships between them. Process theory has been suggested to overcome this problem. Process theory provides a complementary, dynamic perspective on IS phenomena by explaining how independent and dependent variables are linked in terms of event sequences. Although applying both approaches provides more complete pictures of IS phenomena, a lack of research methods focusing on process theories may hinder this goal. This article seeks to help closing this gap by examining how case research can be applied to develop process theory. We analyzed IS case research as well as process research literature and consolidated inputs from both sources toward a single methodology. The results highlight that the development of process theory benefits from a consistent methodology and quality measures that have been suggested in general case research. However, we also found that each step requires specific consideration of process theory characteristics in order to develop rigorous process theory.