Three fundamental observations on the contemporary debate on governance and steering for sustainable development are outlined. First, sustainable development as a highly normative, yet extremely vague concept inescapably raises issues of governance and political steering. Second, the many contributions, approaching sustainability governance from multiple angles, have in common that they assume sustainability goals to a certain extent as given. Third, sustainability poses specific challenges to governance that are different from other policy fields. In this context, exiting contributions highlight issues of complexity, uncertainty or ambivalence, albeit in a rather cursory manner. Against this background, a specific approach is introduced, exploring the complexities that arise from limits to rational steering in three dimensions: Sustainability goals are ambivalent in that they are subject to controversies based on heterogeneous perceptions, values and interests of individuals and societal groups. Moreover, the knowledge of the complex dynamics involving society, technology and nature typically remains highly uncertain. Finally, the power to shape structural change in society and technology is distributed across a multitude of actors and societal subsystems. The article concludes by outlining the structure of the present collection of papers and by summarising each contribution.