Nanotheranostics, combining photothermal therapy (PTT) and photodynamic therapy (PDT), can transform precision cancer treatment by integrating diagnosis and therapy into a single platform. This review highlights recent advances in nanomaterials, drug delivery systems, and stimuli-responsive mechanisms for effective PTT and PDT. Multifunctional nanoparticles enable targeted delivery, multimodal imaging, and controlled drug release, overcoming the challenges posed by tumor microenvironments. Emerging approaches such as hybrid therapies and immune activation further enhance therapeutic efficacy. This paper discusses the limitations of nanotheranostics, including synthesis complexity and limited tissue penetration, and explores future directions toward biocompatible, scalable, and clinically translatable solutions.