Hyperthermia (HT) means using controlled temperatures of 40-45^°C for cancer treatment. HT is applied with different methods e.g. superficial-HT, locoregional deep-HT, interstitial-HT, intracavity-HT, and whole body-HT. HT can apply in different tumor sites such as breast cancer, melanoma, head and neck, cervix cancer, and glioblastoma. Literatures show that addition of HT to radiotherapy, chemotherapy, or both, will result better tumor response rate, local control, and survival rate; without increasing toxicity. HT can also improve palliative effects in patient. In recent years, due to substantial technical improvements made in achieving selected increase of temperatures in superficial and deep-seated tumors, thermometry, and treatment planning; HT is becoming more clinically accepted in Europe and the USA. HT, as an adjunct cancer treatment modality, is certainly a promising approach; however, it is not well known yet worldwide. Therefore, it seems there is need to know more about that. The purpose of this review is to provide an overview on the application of HT combined with conventional cancer treatment modalities, mainly radiotherapy. The article also introduces mechanism of HT, heating delivery modes, thermometry, and it summarizes results of randomized trials form Western research groups.