This book presents a comprehensive exploration of nanotechnology and its transformative applications across medicine and environmental sciences. It highlights how nanoscale innovations are revolutionizing diagnostics, targeted drug delivery, and regenerative medicine, offering new pathways for treating complex diseases. In the environmental domain, the book discusses the role of nanomaterials in pollution control, water purification, and sustainable energy solutions. The integration of nanotechnology with biology, chemistry, and engineering is emphasized, reflecting a truly multidisciplinary approach. Readers will gain insights into the design and synthesis of functional nanomaterials and their safe deployment in real-world systems. The book also addresses the toxicity, biocompatibility, and environmental impact of nanostructures, ensuring a balanced perspective on both their potential and challenges. With contributions from leading researchers, it combines theoretical foundations with practical applications. Case studies and recent developments make this volume an essential reference for students, researchers, and professionals in nanoscience, biomedicine, and environmental technology. It bridges the gap between fundamental research and applied innovation, aiming to foster sustainable and health-focused solutions through nanotechnology.