Abstract This article explores the concept of monstrosity in relation to the development of digital computers during the 1950s in the United States. Discourse analysis of public representations of early digital computers reveals a consistent appropriation of monstrosity as a metaphor to capture cultural fears of human-mechanical hybridity and technological autonomy. Deconstructing the development and application of this metaphor provides valuable insight into cultural attitudes about computers during this period. Through this analysis, the development of the computer appears as simultaneously following its own unique trajectory while also coinciding with broader trends in the cultural histories of new technologies. In particular, the example of the computer epitomises a dichotomy of fear and fascination, which is frequently seen in response to new technologies. Specific examples of early computers that are considered include ENIAC, WHIRLWIND, and UNIVAC. The public representation of and responses to each of these machines demonstrates a fundamental division between admiration at their technical application and concern over their apparently unlimited potential. This dichotomy is identified particularly through examination of contemporaneous popular cultural representations. Images of monstrosity are also shown to be consistent in these public representations, with rhetoric focusing in particular on anthropomorphic machines and human-mechanical hybridity. As a result, the fears of scientific creation encapsulated by Shelley’s depiction of Frankenstein’s monster can be seen to play out over a century later through the ‘mechanical monsters’ of the 1950s United States.