The engineers who studied in Europe in the nineteenth and twentieth centuries and who returned to Greece to work have been seen as bearers of scientific knowledge and the modernising effort. Actually, they were active historical agents contributing with their multiple scientific activities to the process of appropriation of science and technology and industrial modernisation in the specific historical environment. This article aims, through the study of a particular professional group of engineers, the mining engineers, to demonstrate the interaction between scientific and technical professional activities and participation in political and social affairs. For these mining engineers, the technical efficiency and economic growth that industrialisation would bring could not be dissociated from social order and a hierarchical form of social organisation. At the same time, the formation of their professional group, as well as the social organisation that they envisioned, were rooted in gendered and class relations of power.