Radiotherapy for cervical cancer has both beneficial and detrimental effects: improvement of patient survival and potential induction of a second cancer among long-term survivors. Large epidemiological studies have demonstrated small, but significant, increases of second cancers with radiotherapy compared with the general population. The risk of second cancer has been characterized by organ sites, dose, time since radiotherapy and age at the time of radiotherapy. Analyses of genetic susceptibility and molecular carcinogenesis can be used to develop more appropriate strategies for radiation therapy for cervical cancers.