Cancer including lung cancer, rectal and prostate cancer, colon cancer and breast cancer remains the leading cause of morbidity and mortality worldwide. The use of noninvasive imaging technique to detect cancers at an early stage and achieve imageguided cancer therapy provides better opportunities for patients to obtain effective treatment with fewer side effects. To date, photoacoustic (PA) imaging (PAI) is the fastest-growing area of biomedical imaging technology because PAI enables anatomical, functional and metabolic imaging of tumors with high resolution, high contrast and satisfactory penetration depth. However, the sensitivity of PAI to visualize tumors is determined by its endogenous contrast. By contrast, multifunctional nanoprobes have exhibited their potentials as theranostic agents for PAI-guided cancer theranostics.