Project managers commonly adopt suboptimal work plans, even when optimal plans are readily accessible. This research identifies a factor that elicits this seemingly irrational behavior: the perceived complexity of the optimal work plan, as reflected in the plan’s Gantt chart representation. Four controlled experiments show that among experienced project managers presented with a work plan explicitly stated to be optimal, those who view a low-complexity plan are more likely to adopt the plan compared with project managers who view a high-complexity plan. Work-related stress triggered by exposure to the work plan is shown to mediate the effect.