Introduction: Driving competency is important to evaluate among individuals with Parkinson’s disease (PD). Driving in natural situations is the preferred assessment method; thus, we used a naturalistic driving environment to identify driving competency among individuals with PD in comparison to healthy age-matched controls. Methods: Based on a power analysis, we recruited 20 participants (10 with PD and 10 healthy age-matched controls). Each participant completed 3 tasks while driving the ChulaPD car, a 4-door sedan installed with computerized monitoring systems. The tasks were forward and backward vehicle movement, reversing into a parking space, and parking parallel to a sidewalk. Trip start and end times, vehicle speed, and acceleration and deceleration times were logged using steering wheel motion, location parking sensors, and dashboard cameras and compared between groups. Results: Age, gender, possession of a driver’s license, present driving conditions, Thai Mini-Mental State Examination score, and driving experience did not significantly differ between groups. However, the PD group took longer to complete the driving tests (p = 0.002), had slower vehicle speeds (p = 0.002), longer brake times (p = 0.007), and decreased brake pressure ability (p = 0.009). Under normalized conditions, the ratio of failed driver’s license tests was also higher among the PD group than in the control group (70 vs. 10%, p = 0.006). Conclusions: Individuals with PD had less-than-adequate driving ability based on our naturalistic setting. Our assessment method may be useful in other populations with chronic illnesses or for older adults. We discuss how naturalistic assessments could become the standard for evaluating driving ability in Thailand and elsewhere.