Objective To analyse and compare the treatment outcome of the patients with gestational trophoblastic neoplasia (GTN) who were transferred to the Peking Union Medical College Hospital (PUMCH) because of chemoresistant or relapsed GTN. Design A retrospective study of the clinical features and treatment outcome of GTN after treatment failure elsewhere at the PUMCH. Setting The Department of Obstetrics and Gynecology, PUMCH, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China. Population A total of 81 women with chemoresistant or relapsed GTN transferred and treated between January 2005 and December 2007. Methods A review of medical records of consecutively collected, referral cases of GTN was performed. The patients were classified according to the reasons for referral as having chemoresistant GTN if they had an incomplete response to previous treatment, and as having relapsed GTN if they had elevated serum β-human chorionic gonadotropin (β-hCG) levels, in the absence of a pregnancy, after the completion of initial treatment. Main outcome measures Serologic complete remission (SCR) and relapse rates. Results The patients with chemoresistant and relapsed GTN achieved 52.6 and 76.7% of the long-term SCR rate, respectively; P = 0.035. Relapse rate and median time to relapse were similar between the chemoresistant GTN cohort and the relapsed GTN cohort after initial SCR (24 versus 35.7%, P = 0.417; 4 versus 3 months, P = 0.969). Conclusions The patients with chemoresistant GTN had a worse outcome compared with patients with relapsed GTN. The importance of obtaining a normal β-hCG level with treatment for GTN should be emphasised, and novel therapies should be pursued for these patients. © RCOG 2009 BJOG An International Journal of Obstetrics and Gynaecology.