Purpose: Recommendations for antiemetic prophylaxis supportive to radiotherapy and concomitant chemotherapy are not evidence-based. The purpose of this study was to evaluate the efficacy of the antiemetic regimen concurrent to fractionated radiotherapy and concomitant weekly cisplatin in two Danish departments of oncology. Methods: Patients with gynecological cancer scheduled to receive fractionated radiotherapy and concomitant weekly cisplatin (40 mg/m2) were asked to complete a study diary in order to assess episodes of emesis, grade of nausea, and use of rescue antiemetic treatment daily during 5 weeks of treatment. Antiemetic treatment consisted of palonosetron and prednisolone. A patient had completed the study if emesis occurred or if 5 weeks of treatment were accomplished without emesis. The primary endpoint was sustained no emesis during 5 weeks of treatment. Results: A total of 48 patients completed 155 weekly cycles of radiotherapy, concomitant weekly cisplatin, and antiemetic prophylaxis. The probability of completing 5 cycles without emesis (sustained no emesis) was 57 %. During cycle 1, 42 % of the patients were free from nausea. After 5 cycles, only 23 % of patients were continuously free from nausea. One half of the patients used rescue antiemetic treatment at least once during the 5 cycles. Conclusion: The present study demonstrates that an antiemetic prophylaxis consisting of palonosetron and prednisolone is insufficient for the prevention of nausea and vomiting induced by radiotherapy and weekly cisplatin in patients treated for gynecological cancer. The addition of a neurokinin-1 receptor antagonist should be investigated in a randomized, double-blind study in this setting.