This Brief Report describes the research and key lessons learned in the initial four-year phase of the research program Mistra Sustainable Consumption that seeks to stimulate a transition to more sustainable consumption in Sweden. The program is transdisciplinary and includes approximately 20 researchers and a similar number of societal partners from the public, private, and civil society sectors. The aim of this report is to summarize the findings from the program about how and under what conditions potentially sustainable niche practices can become more mainstream and how such a transition can be enabled through civil society, business models, and policy innovation. The thematic focus of the program is on practices related to home furnishing, vacationing, and eating and we have identified potentially sustainable consumption practices, analyzed several of them with respect to their environmental and social impacts, and highlighted potential enablers for mainstreaming such practices. One key conclusion is that it is possible to reduce greenhouse-gas emissions by approximately 40 percent by changing customary consumption practices without the need for large investments or new policies. This is an encouraging finding, but it is not adequate to meet the goals of the Paris Agreement. Therefore, more fundamental changes will be needed, including the exploration of sufficiency-oriented policy tools.