The aim of this study was to assess the role of Action Observation (AO) to improve balance, gait, reduce falls, and to investigate the changes in P300 pattern. Five cognitively intact People with Parkinson’s disease (PwP) were enrolled in this prospective, quasi-experimental study to undergo a rehabilitation program of AO for gait and balance recovery of 60 min, three times a week for four weeks. The statistical analysis showed significant improvements for Unified Parkinson’s Disease Rating Scale (UPDRS) motor section III p = 0.0082, Short form 12-items Healthy Survey (SF-12) Mental Composite Score (MCS) p = 0.0007, Freezing of gait Questionnaire (FOG-Q) p = 0.0030, The 39-items Parkinson’s Disease Questionnaire (PDQ-39) p = 0.100, and for P300ld p = 0.0077. In conclusion, AO reveals to be a safe and feasible paradigm of rehabilitative exercise in cognitively preserved PwP.