Background: A 27-year-old woman with upper mediastinum stage IIA Hodgkin lymphoma was treated with six cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine chemotherapy. Two months later she received a total of 4,250 cGy to the upper mediastinum and left clavicular region over a 1-month period. One week after completion of radiotherapy she was found to be 13-weeks pregnant. Her physician advised her to terminate pregnancy. She contacted a teratology information service for further information regarding the risks of radiation exposure for her fetus. Investigations: Estimation of fetal radiation exposure, literature review and synthesis of published cases and effects of fetal radiation exposure. Diagnosis: Estimated fetal radiation dose between 5 and 18 cGy. Management: Counseling on the possible risks to the fetus as a result of radiation exposure.