BACKGROUND: Parkinson's disease (PD) is a neurodegenerative disorder characterized by the loss of dopamine-producing neurons, which results in motor issues such as tremors, stiffness, and slowness of movement. In addition to experiencing non-motor symptoms like psychosis. Catatonia, a psychomotor syndrome that is resulted from dopamine and cerebral cortical dysfunction, is considered a rare manifestation of PD patients. Acromegaly, a hormonal disorder caused by excessive growth hormone, often due to pituitary adenomas, can worsen cognitive and psychiatric symptoms. This case report demonstrates how lorazepam resulted in the full resolution of both catatonia and psychosis in a PD patient with acromegaly. CASE PRESENTATION: A 78-year-old woman, known case of PD and major depressive disorder, presented to our hospital after the discontinuation of all her medications and worsening of her symptoms. She had significant neuropsychiatric symptoms that were resistant to treatment with various approaches. Her symptoms, which were consistent with catatonia and psychosis, was completely alleviated by taking lorazepam, along with restarting levodopa. Brain Magnetic Resonance Imaging (MRI) showed a pituitary macroadenoma, and hormonal studies verified acromegaly. Within six days of initiating lorazepam treatment, both catatonia and psychosis completely resolved, with an overall improvement of approximately 50%. CONCLUSION: This case highlights the importance of recognizing catatonia and psychosis as possible complications of PD, especially in the context of medication withdrawal and comorbid acromegaly. These neuropsychiatric symptoms were successfully resolved by lorazepam, demonstrating the medication's effectiveness in treating complex co-occurring disorders.