Gold nanoparticles (AuNP) with excellent optical and localized surface plasmon resonance properties have received intensive attention in biomedical applications. To achieve good therapeutic efficacy and minimize side effects in cancer treatment, increasing efforts have been made to combine therapeutic, imaging and targeting functions together in one drug delivery system. Polymer/gold hybrid nanoparticles are appealing for cancer treatment because they can be used as various theranostic modalities, including photothermal therapy (PTT), photodynamic therapy (PDT), chemotherapy, and imaging probes as well. Furthermore, the combination of more than one therapy methods that shows synergistic effect and good therapeutic efficacy in cancer treatment can be achieved by the polymer/AuNP hybrids. This minireview highlights the preparation methods for various polymer/AuNP hybrids and the recent progress on their cancer theranostic applications.