Working toward a sustainable environment and society has never been as high a priority as it is today. Numerous studies worldwide have concluded that if no actions are taken, it will be too late to ensure the survival of future generations. Sustainability entails fundamental changes in the way organizations and societies have been working, the way products and services have been produced, and the way environment, economy and society have been interacting with each other. Design consultancies operate at the initial stages of product development and can contribute significantly to design and production of sustainable goods. This thesis aims to understand and identify how design consultancies can be an active part of a system transformation required to achieve sustainability. It is a case study carried out at a design consultancy Prevas AB in Uppsala, Sweden. Sustainability is a complex topic and its integration into business practices is seldom easy. The objective of the study is to assist design consultancies in addressing this challenge of integrating sustainability. A comprehensive literature review on sustainability, sustainable design practices, role of design consultancies in product development is presented. A qualitative approach with semi-structured interviews is followed to understand the current situation in the market, the perception of sustainability by various stakeholders, and potential improvement areas. The thesis underlines the need and importance of making investments for integrating sustainability at design consultancies, along with some recommendations and practical suggestions to implement related practices. With an analytical approach, integrating sustainability at design consultancies is discussed as an innovation, and the business opportunities involved in adopting this innovation are identified. The results show that although design consultancies may not independently drive the sustainability in product development, they can surely play an important part in it and the current timeframe is critical for making related investments.