Summary This paper explains the coexistence of concerns about hereditary degeneration and opposition to reproductive intervention such as sterilisation in Dutch eugenic discourse during the interwar years. Based on an analysis of textbooks, periodical publications and printed lectures, I will show how eugenicists positioned themselves within the domain of public health by framing their domain of inquiry as a pivotal addition to curative medicine and sanitary reform. Dutch eugenicists rendered this symbiotic relationship conceptually plausible by combining criticism of genetic determinism and Lamarckian viewpoints on heredity. This paper explains how this conceptual constellation enabled Dutch eugenicists to claim that the combination of proper (eugenic) education and a healthy environment would stimulate individuals to behave socially responsibly and restrain from reproducing. By doing so, this essay contributes to the historiographical trend to comparatively analyse eugenics as a transnational phenomenon.