This survey was performed in order to investigate the incidence of adverse reactions to radiopharmaceuticals in FY2018 in Japan. It was based on the responses to questionnaires sent to nuclear medicine institutions. Replies were obtained from 999 institutions among 1,230 to which the questionnaire had been sent. Fourteen cases of adverse reactions were reported. A total of 1,017,702 radiopharmaceutical administrations were reported. The incidence of adverse reactions per 100,000 cases was 1.4. No case of deficient products was reported.