This book offers an exploration of diagnostic tools and techniques essential for accurate evaluation and treatment planning in prosthodontics. It begins with foundational knowledge such as history taking and diagnostic casts and progresses into advanced imaging modalities including CBCT, MRI, and 4D imaging. Emphasizing both conventional and digital innovations-from T-Scan occlusal analysis to resonance frequency evaluation and salivary diagnostics-it provides a structured approach to diagnosis across complete dentures, removable and fixed prostheses, implantology, and maxillofacial prosthetics. An essential resource for postgraduate students and clinicians aiming for precision in prosthodontic rehabilitation.