A clinical investigation of adverse events was conducted to confirm the safety of concurrent chemotherapy using nedaplatin (cisplatin derivative) and radiotherapy in the high-risk carcinoma of the uterine cervix. Seven patients who were treated with radical radiotherapy and 5 patients who were treated with adjunctive radiotherapy after radical hysterectomy and pelvic lymphadenectomy were eligible for the study. Nedaplatin was given intravenously at 70 mg/m2 on day 1 and day 29, and a total of 24 courses of nedaplatin administration were observed. None of the planned radiotherapy was postponed or discontinued due to side effects. Major adverse effects observed were gastrointestinal effects such as anorexia (66.7%), nausea and vomiting (33.3%) and diarrhea (66.7%). Grade 3 (in the 2nd course) and Grade 4 (in the 1st course) diarrhea was observed in one patient, which was easily relieved by antidiarrheal. Hematologic side effects were also major, including leukopenia (62.5%), neutropenia (75.0%), anemia (75.0%), and thrombocytopenia (33.3%). Hematologic effects were generally moderate; no Grade 4 (severe) effects were observed. Although these hematologic effects were lasting longer compared with radiation therapy alone, there were no significant differences in the seriousness of these side effects. Concurrent chemoradiation therapy with nedaplatin 70 mg/m2 every 4 weeks was safe and adverse effects were self-limited or resolved with medical management. Dose escalation in the phase III clinical study may be considered.