Facial expressions are critical in forming social bonds and in signalling one's emotional state to others. In eating disorder patients, impairments in facial emotion recognition have been associated with eating psychopathology severity. Little research however has been carried out on how bulimic spectrum disorder (BSD) patients spontaneously express emotions. Our aim was to investigate emotion expression in BSD patients and to explore the influence of personality traits. Our study comprised 28 BSD women and 15 healthy controls. Facial expressions were recorded while participants played a serious video game. Expressions of anger and joy were used as outcome measures. Overall, BSD participants displayed less facial expressiveness than controls. Among BSD women, expressions of joy were positively associated with reward dependence, novelty seeking and self‐directedness, whereas expressions of anger were associated with lower self‐directedness. Our findings suggest that specific personality traits are associated with altered emotion facial expression in patients with BSD. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.