Photothermal therapy (PTT) and photoacoustic imaging (PAI) using nanotheranostics have shown great promise in cancer treatment. This review summarizes the development of inorganic and organic photothermal transduction agents (PTAs) and strategies to enhance PTT outcomes, including optimizing laser dosage, using imaging techniques for treatment guidance, developing PTAs with absorption in the second near-infrared (NIR) window, improving photothermal conversion efficiency (PCE), and increasing PTA accumulation in tumors. It also discusses the advantages of combining PTT with other therapies and the emerging applications of PAI in cancer research. The review highlights the potential of PTT and PAI as next-generation non-invasive cancer theranostic techniques, emphasizing their clinical translation challenges. Noble metal materials, such as gold (Au), silver (Ag), platinum (Pt), and palladium (Pd), are widely studied as PTAs. Au-based PTAs, particularly Au nanorods, have been extensively researched due to their high PCE and tunable absorption properties. However, they face challenges such as toxicity and limited photothermal stability. Pd and Pt-based PTAs offer better photothermal stability and some catalytic properties. Graphene and its analogues, including transition metal dichalcogenides (TMDs), transition metal oxides (TMOs), MXenes, and black phosphorus, have also been explored for their photothermal properties and biocompatibility. These materials exhibit strong NIR absorption and good photothermal performance. Small molecule-based PTAs, such as cyanine dyes and porphyrins, have been used for PTT and PDT. Cyanine dyes, like indocyanine green (ICG), have high molar extinction coefficients and are suitable for PTT. However, they are prone to photobleaching. Porphyrins, such as Photofrin and Visudyne, are approved for PDT but face challenges with solubility and toxicity. Recent advances in supramolecular structures, such as porphysomes, have improved PTT efficiency by enhancing tumor accumulation and photothermal conversion. Semiconducting polymer nanoparticles (SPNPs) have shown excellent optical properties and photothermal efficiency. Conducting polymers like polyaniline (PANI) and polypyrrole (PPy) are promising PTAs due to their ability to absorb NIR light and generate heat. These materials have been used in combination with other therapies to enhance treatment outcomes. The review concludes that PTT and PAI, when combined with nanotheranostics, offer significant potential for cancer treatment, although challenges such as clinical translation and biocompatibility remain to be addressed.Photothermal therapy (PTT) and photoacoustic imaging (PAI) using nanotheranostics have shown great promise in cancer treatment. This review summarizes the development of inorganic and organic photothermal transduction agents (PTAs) and strategies to enhance PTT outcomes, including optimizing laser dosage, using imaging techniques for treatment guidance, developing PTAs with absorption in the second near-infrared (NIR) window, improving photothermal conversion efficiency (PCE), and increasing PTA accumulation in tumors. It also discusses the advantages of combining PTT with other therapies and the emerging applications of PAI in cancer research. The review highlights the potential of PTT and PAI as next-generation non-invasive cancer theranostic techniques, emphasizing their clinical translation challenges. Noble metal materials, such as gold (Au), silver (Ag), platinum (Pt), and palladium (Pd), are widely studied as PTAs. Au-based PTAs, particularly Au nanorods, have been extensively researched due to their high PCE and tunable absorption properties. However, they face challenges such as toxicity and limited photothermal stability. Pd and Pt-based PTAs offer better photothermal stability and some catalytic properties. Graphene and its analogues, including transition metal dichalcogenides (TMDs), transition metal oxides (TMOs), MXenes, and black phosphorus, have also been explored for their photothermal properties and biocompatibility. These materials exhibit strong NIR absorption and good photothermal performance. Small molecule-based PTAs, such as cyanine dyes and porphyrins, have been used for PTT and PDT. Cyanine dyes, like indocyanine green (ICG), have high molar extinction coefficients and are suitable for PTT. However, they are prone to photobleaching. Porphyrins, such as Photofrin and Visudyne, are approved for PDT but face challenges with solubility and toxicity. Recent advances in supramolecular structures, such as porphysomes, have improved PTT efficiency by enhancing tumor accumulation and photothermal conversion. Semiconducting polymer nanoparticles (SPNPs) have shown excellent optical properties and photothermal efficiency. Conducting polymers like polyaniline (PANI) and polypyrrole (PPy) are promising PTAs due to their ability to absorb NIR light and generate heat. These materials have been used in combination with other therapies to enhance treatment outcomes. The review concludes that PTT and PAI, when combined with nanotheranostics, offer significant potential for cancer treatment, although challenges such as clinical translation and biocompatibility remain to be addressed.