Purpose: Patients with Parkinson's disease suffer many restrictions in daily life. This case report investigated how intervention with proprioceptive neuromuscular facilitation (PNF)-based physical therapy can affect the activities of Parkinson's patients. Methods: The subject was a 67-year-old female patient diagnosed with Parkinson's disease 3 years ago. Since the last five months, overall activities have become difficult for her, and she finally visited a hospital to take outpatient physical therapy because of the gait difficulties she suffered. The patient's medical history, system review, body structure and function, and activities were evaluated. The patient had difficulties in activities such as lying down, sitting, standing, maintaining a standing position, and walking. The PNF-based intervention was used for treating the impairments and improving the activities. The intervention was performed for 30 min a day, three times a week, for eight weeks. The qualifier of the international classification of functioning, disability, and health was used to measure the result, and the measurement was conducted before and after the intervention for eight weeks. Results: According to the result, the scores for maintaining a standing position, moving around within the home, and going to the toilet improved to "no problem" from "moderate problem." The scores for shifting the body's center of gravity, walking short distances, and washing oneself improved from "moderate problem" to "mild problem." The scores for sitting and standing improved to "no problem" and "mild problem" from "complete problem." The scores for preparing meals and doing housework improved from "severe problems" to "mild problem" or "moderate problem." The scores for walking long distances, moving around outside the home and other buildings, and using transportation did not show significant changes. Conclusion: Intervention with PNF-based physical therapy improved the activity of patients with Parkinson's disease, thus proving its effectiveness. The case report suggested that a therapist can use PNF as a physical therapy intervention for patients with Parkinson's who suffered restrictions in daily activities.