This study investigates the synergies among blockchain technology, artificial intelligence (AI), and green cybersecurity practices to enhance sustainability within digital infrastructures, addressing the pressing challenge of how these technologies can collaboratively mitigate cybersecurity threats while promoting environmental sustainability. Using data obtained from cybersecurity case studies, technological efficacy reports, and assessments of energy consumption related to blockchain and AI applications across various industries, the research reveals that integrating these technologies significantly reduces energy consumption and enhances threat detection and response capabilities. Key findings indicate that a synergistic approach not only improves the resilience of cybersecurity frameworks but also contributes to environmental goals by decreasing the carbon footprint associated with digital operations. In the context of healthcare, these insights are particularly significant, as they suggest that adopting such integrated technologies can lead to improved data security, patient privacy, and operational efficiency in a sector increasingly reliant on complex digital infrastructures. This research underscores the vital intersection of technology and sustainability, offering a pathway for future innovations in the realm of secure and eco-friendly digital infrastructure.