Sustainable entrepreneurship pursues a triple bottom line approach of economic, social and ecological goals. The main aim of this paper is to add to our understanding of the process of sustainable entrepreneurship. Since the field of sustainable entrepreneurship is in a nascent stage, we conduct a qualitative study. We employ a multiple case study design to build theory. Based on four case studies we develop a model, which describes the process of sustainable entrepreneurship, including six phases: 1) recognizing a social or ecological problem; 2) recognizing a social or ecological opportunity; 3) developing a double bottom line solution; 4) developing a triple bottom line solution; 5) funding and forming of a sustainable enterprise; 6) creating or entering a sustainable market. By developing a convergent process model with two pathways, we make theoretical contributions to the emerging fields of sustainable entrepreneurship and social entrepreneurship. A key finding is that the triple bottom line of ecological, social and economic goals is integrated sequentially, not simultaneously. Copyright © 2015 John Wiley & Sons, Ltd and ERP Environment.