The purpose of this study was to explore the influence of neurofeedback on engineering design ideation. Professional civil engineers (n = 122) were randomly divided into three groups: to receive neurofeedback, fake feedback that was pre-recorded (active control), or no feedback (control). The neurofeedback intervention provided designers with a dynamic heatmap displaying oxygenated hemoglobin (oxy-Hb) in their prefrontal cortex (PFC). The feedback groups were told to maintain the oxy-Hb in their PFC while ideating based on the heatmap. Designers verbalized their responses to the ideation tasks. Their verbalizations were recorded and transcribed. The time designers spent ideating and the number of words used to describe their design concepts were used as metrics for comparisons. The results indicate a significant increase in both the time designers spent ideating and the number of words used to describe their design concepts in the neurofeedback group compared to the other two groups. This research begins to highlight the potential use of neurofeedback as a tool to enhance design cognition. Future research is needed to explore changes in concepts, creativity, and idea production.