Gene drives are technologies that modify a particular genetic element in animals or insects so that this genetic element does not follow the typical rules of heredity, and is passed onto future generations with an increased likelihood. Gene drive technologies could be used to tackle intractable problems such as vector-borne diseases like malaria or the biodiversity impact of invasive species. At the same time, the development and governance of gene drives raise a range of ethical questions and concerns that warrant proactive ethical evaluation. In the PhD thesis ‘Gene drive technologies: navigating the ethical landscape’, Nienke de Graeff analyzes these questions and concerns. In Part I, she outlines the ‘ethical landscape’ of gene drive technologies by identifying the associated ethical challenges through literature review and empirical ethical research. Important challenges concern how the uncertainty and risks of these technologies should be navigated, whether it is morally permissible to intervene in nature in this way, and how the development, governance, and potential deployment of gene drive technologies should be guided. In Part II, De Graeff normatively analyzes various of these challenges and provides guidance to navigate them. In Part III, she stipulates recommendations for researchers and policymakers in the gene drive field as well as lessons learned for ethics parallel research as an approach for early ethical guidance of new and emerging technologies more generally.