Neurodegenerative diseases are the result of neurodegeneration, which is the process of losing neuronal functions gradually due to the irreversible damage and death of neurons. Metal complexes have attracted intense interest over recent decades as probes or inhibitors of biomolecules. In this review, we discuss the application of transition metal complexes in the diagnosis and therapy of different neurodegenerative diseases. We first briefly introduce conventional approaches for the diagnosis and treatment of neurodegenerative diseases. Then, the characteristics and mechanisms of transition metal complexes as luminescent probes and drug candidates are discussed. Representative examples of the use of metal complexes in targeted detection and treatment of neurodegenerative diseases are highlighted. Finally, the challenges and future perspectives of this field are presented.