Designing successfully for any new or unfamiliar manufacturing technology requires an ability to look beyond the manufacturing limitations that have constrained one’s design ideas in the past. However, potential cognitive bias or fixation on familiar manufacturing processes may make this a challenge for designers. In this paper we introduce the novel concept of Manufacturing Fixation in Design (MFD), which we define as unconscious and often unintentional adherence to a limited set of manufacturing processes and/or constraints and capabilities during the design ideation process. This concept is explored as a subset of design fixation, a cognitive bias often experienced by designers and engineers. After reviewing related literature in design fixation, we introduce MFD as a type of design fixation and explore ways in which fixation on manufacturing might be assessed. We then offer an exploratory case study involving design for additive manufacturing, an advanced manufacturing technology that has seen considerable interest lately. The case study involves a Design for Additive Manufacturing workshop given at an aerospace technology company headquartered in the United States with participants who are professional engineering designers. Results from the study are used to explore how MFD manifests and how its impact in design and optimization for manufacturing might be measured. Future research and next steps to validate the existence of MFD are also discussed.