We examine various, sometimes divergent, conceptions of capital and its structure in the Austrian tradition from Menger (1871) to Lachmann (1956). We outline Menger’s methodological and philosophical position that recommends investigation of the morphology of capital—its shape, form and structure; it also recommends maintaining some ‘realisticness’ in the treatment of capital in economics. Prominent Austrian contributions are examined and compared along various dimensions: the existence or otherwise of ‘original’ factors of production; capital aggregation into a stock or fund; time conceptions; analytical domain assumptions, real versus money capital doctrines and the causal role of the entrepreneur in creating capital. We consider the extent to which Menger’s avowed followers and successors diverged from his original vision of capital, subsequent consequences for the development of Austrian capital theory and implications for the study of capital more generally.