Design in many settings is an inherently collective and creative undertaking, with phenomena of emergence at the heart of the activity. Cognitive accounts of emergence in the context of design have not taken its collective nature into account. At the same time, accounts of collective emergence do not recognise certain salient attributes of design, including the importance of visual thinking and various media for external representation. With reference to two distinct theories of emergence, Oxman's account of design emergence in terms of visual cognition, and Sawyer's account of collaborative emergence in conversation and performance, this paper reports results from a study of a high-performing, technologically mediated concurrent design practice. On-site observation, interviews, and video interaction analysis were used to render the creative process of engineering design in fine-grained detail. The resulting insights support aspects of both theories in that creative activity appears to proceed substantially through modalities of visual cognition, while collaborative products are arrived at through an essentially collective process involving multiple participants and unpredictable developments. The combined view presents a richer picture of collective emergence in design than either theory alone provides. © 2010 Taylor & Francis.