To investigate the utility of neural theories for human planning, this study used near-infrared spectroscopy to investigate prefrontal (PFC) oxygenation for a well-established planning task: The Tower of London (TOL). Changes in prefrontal oxygenated hemoglobin from baseline were measured during task performance. Performing the Tower of London led to a significant increase in oxygenation in the left caudal region of the PFC in difficult trials moves relative to easier trials. The different degree of prefrontal oxygenation agrees with previous research and provides further evidence for a capacity utilization framework for measuring neurocognitive demand. Higher activity in the left rostral frontopolar region predicted better performance in the Tower of London, which agrees with a proposed rostral-caudal control hierarchy for the prefrontal cortex. Observed results support the feasibility of near-infrared spectroscopy to assess activity during tasks requiring planning ability and provide support for two neurocognitive models, capacity utilization and rostro-caudal control hierarchy.