Green product innovation has been recognized as one of the key factors to achieve growth, environmental sustainability, and a better quality of life. Understanding green product innovation as a result of interaction between innovation and sustainability has become a strategic priority for theory and practice. This article investigates green product innovation by means of a multiple case study analysis of 12 small to medium size manufacturing companies based in Italy and Canada. First, we propose a conceptual framework that presents three key environmental dimensions of green product innovation such as energy minimization, materials reduction, and pollution prevention as identified in the life cycle phases of products. Based on insights gained from in-depth interviews, we discuss firms' motivations to develop green products, environmental policies and targets for products, different dimensions of green product innovation, and challenges faced during developing and marketing of green products. Results from the study are then synthesized and integrated in a toolbox that sheds light on various aspects of green product innovation and provides solutions to challenges and risks that are faced by firms. Finally, implications for managers, academia and public policy makers are discussed.