This paper analyses the role of a code of ethics for judges in connection to a contemporary definition of responsive ‘T-shaped’ judicial professionalism and the professional-ethical questions which can arise in judicial decision-making regarding politically and societally controversial issues. The paper’s case study focuses on climate-change related litigation in Dutch courts. First, a theoretical framework which conceptualises practical and ethical elements of T-shaped judicial professionalism as ‘virtuous judgecraft’, building on the work of Kritzer and Van Domselaar, addresses the knowledge, skills, and ethical mindset that judges need for fulfilling their roles in relation to this notion of professionalism. Next, the paper analyses to what extent connections with guidelines of the Dutch Guide to Judicial Conduct (GJC), considered in light of the developed framework of virtuous judgecraft, can be recognised in the approaches of judges in the landmark Urgenda judgments. Based on this analysis, the paper presents conclusions regarding the value of the GJC for enhancing judicial performance and for explaining judgments, in particular those which involve complex societal issues, to parties and the general public.