The management of individuals with dual diagnoses of mental health disorders and intellectual disabilities (ID) presents unique challenges in psychiatric nursing care. These patients often require highly specialized interventions, as their treatment demands an understanding of both their psychiatric conditions and their cognitive limitations. The current review aims to explore the complex role of psychiatric nurses in providing comprehensive care to individuals with dual diagnoses. It highlights key issues such as diagnostic overshadowing, communication barriers, stigma, and the necessity of an interdisciplinary care approach. Furthermore, this review underscores the importance of evidence-based practices, such as Cognitive Behavioral Therapy (CBT), Positive Behavioral Support (PBS), and trauma-informed care, in enhancing patient outcomes.