Question: Non-pharmacologic treatment such as physical exercise has been proven to have beneficial effects on gait disorders in Parkinson's disease (PD). In Lyon (France), Sirroco rehabilitation program is a novel, collective, multidisciplinary program focused on intensive, high amplitude movements, and loudness of speech for patients with PD. However, the effects of physical exercise on dorsolateral prefrontal cortex (DLPFC) activity in patients with PD is still elusive. The main aim of this pilot study was to assess the effects of the Sirocco program in patients with PD on DLPFC activity on single task (ST) and dual-task (DT) walking. Methods: Fourteen PD patients (mean: 66.9 y.o ± 8.1) completed Sirocco sessions for 5 weeks. Changes in oxyhemoglobin concentration (?HbO2) in the DLPFC were measured using functional Near Infrared Spectroscopy during three walking tasks conditions: (1) ST walking, (2) DT walking while counting forward and (3) DT walking while subtracting. Participants were assessed three times: five weeks before the program (T0); few days before (T1) and one week after the program (T2). Walking performance (mean stride time and cadence) was also recorded using foot-sensors. The gain in performance was calculated by subtracting values at T0 and T1 or at T2 and at T1. Results: Significant differences were observed in ?HbO2 between the three times only for the ST walking: ?HbO2 were significantly higher at T1 than at T0 whereas ?HbO2 was lower in T2 than in T1 (p