Problem & Purpose: One-third of acute stroke patients experience post-stroke depression, which is associated with poor functional outcomes, mortality, and increased neurological deficit. The American Stroke Association recommends screening for post-stroke depression using a structured depression inventory. A report showed only 4% of patients with ischemic stroke were screened for post-stroke depression on a neurology unit in a large hospital. The purpose of this quality improvement project was to improve the early identification and treatment of post-stroke depression among ischemic stroke patients on an acute neurology unit by implementing and measuring adherence to a nursing algorithm that includes administering the Patient Health Questionnaire-9 (PHQ-9) tool and subsequent treatment for positive scores. Methods: The Project Lead organized an interdisciplinary team to create a nursing algorithm for identifying and treating post-stroke depression (PSD) in ischemic stroke patients. The algorithm involved screening non-aphasic patients with the PHQ-9 tool within three days of admission. If the score was 10 or higher, nurses alerted the provider for evaluation and treatment. If the PHQ-9 score was five to nine, depression education was included in discharge paperwork. Results: Depression screening rates increased from 0% to 100%, stabilizing between 75% and 100% after week nine, indicating a meaningful process change. Among patients with a PHQ-9 score of 10 or greater, 67% received treatment, 16.5% received no treatment, and 16.5% were not clinically depressed. All patients with a PHQ-9 score of five to nine received depression education. Conclusion: Implementation of the PHQ-9 nursing algorithm increased depression screening and treatment rates, and improved identification and treatment of post-stroke depression.