Quality of life (QOL) has recently become one of the most important focuses in oncology nursing practice and research. The aims of this study were to evaluate the QOL in Chinese cancer patients under chemotherapy and to explore the discrepancy between patients’ and nurses’ assessments of the patients’ conditions. The study participants included gestational trophoblastic disease patients (n = 68), ovarian cancer patients (n = 105), patients with other gynaecological cancer (n = 18), and their attending nurses (n = 25) at hospitals affiliated with universities in Beijing. The high level of some symptom subscales/items in patients suggested that innovative and more effective interventions should be developed and utilised in nursing practice. Patients with metastasis reported lower levels of QOL than those without metastasis. The nurses in this study tended to estimate the patients’ QOL inaccurately, except for a few objective aspects. The results of this study can help nurses in planning interventions to enhance the QOL of patients with gynaecological cancer undergoing chemotherapy. The nurses need to be trained to become more sensitive and competent in assessing patients’ subjective information.