By the early 1990s, sustainable product innovation (or ecodesign, or Design for environment) had gained sufficient critical mass in academic research to be identified as a distinct research area. In the past 15 years, stimulated by a growing environmental concern and awareness in the media, this research area has expanded considerably; from a bunch of opportunistic eco-pathfinders trying to make products better recyclable into acknowledged scientific research regarding technology transfer and commercialisation. This paper proposes that this maturing process took place through a number of transitions; this is illustrated by discussing characteristic aspects of each transition, which together provide a historic account of how academic research into sustainable product innovation had matured. In conclusion, a number of possible future transitions or extensions of the research area are discussed.