Olaparib (Lynparza, formerly referred to as AZD2281 or KU-0059436), is a highly potent polyadenosine diphosphate ribose polymerase (PARP) inhibitor and the first in class approved for use in monotherapy (including maintenance therapy) as well as in combination with other chemotherapeutic agents. It is available in two strengths, 150mg and 100mg. The recommended dosage for Olaparib is 300mg (two 150mg tablets) taken twice daily, resulting in a total daily dose of 600mg. The 100mg strength tablet is used for dose reduction purposes. In August 2018, based on the findings of the trials, Assessment of Efficacy of AZD2281 in Platinum Sensitive Relapsed Serous Ovarian Cancer (Study 19, NCT00753545) and Olaparib Treatment in Breast Cancer Gene (BRCA) Mutated Ovarian Cancer Patients After Complete or Partial Response to Platinum Chemotherapy (SOLO-2, NCT01874353), China National Medical Products Administration (NMPA) approved Olaparib tablets for the maintenance treatment of adult patients with platinum-sensitive recurrent epithelial ovarian cancer, fallopian tube cancer,or primary peritoneal cancer who have achieved a complete or partial response to platinum-bSAEd chemotherapy. In November 2019, based on the results of the trial, Olaparib Maintenance Monotherapy in Patients With BRCA Mutated Ovarian Cancer Following First Line Platinum Based Chemotherapy (SOLO-1, NCT01844986), Olaparib received approval for the maintenance treatment of treatment-naïve adult patients with advanced epithelial ovarian, fallopian tube, or primary peritoneal cancer who have germline BRCA mutations (gBRCAm) or somatic BRCA mutations (sBRCAm) and have achieved a complete or partial response to first-line platinum-based chemotherapy in China. Furthermore, in September 2022, based on the in PAOLA-1 study in front-line advanced ovarian cancer (NCT02477644), Olaparib in combination with Bevacizumab was approved for the maintenance treatment of adult patients with homologous recombination deficiency (HRD)-positive advanced epithelial ovarian, fallopian tube, or primary peritoneal cancer who have achieved a complete or partial response to first-line platinum-based chemotherapy in China. Lynparza has been reported to be associated with mild or moderate adverse reactions \[grade 1 or 2 according to the Common Terminology Criteria for Adverse Events (CTCAE)\] and generally not requiring treatment discontinuation. In accordance with the Measures for the Administration of Adverse Drug Reaction Reporting and Monitoring (Order No.81 of the Ministry of Health), it is recommended to monitor the safety profile of newly approved drugs in real-world settings. Post-marketing real-world studies closely reflect clinical practice and provide a comprehensive understanding of the product's safety profile compared to premarketing Phase II/III studies. Currently, there is a limited number of safety studies focusing on Chinese patients with ovarian cancer conducted in routine clinical practice, and these studies have small sample size. This study aims to assess the safety of Olaparib in Chinese ovarian cancer patients treated in real-world clinical practice by retrospectively analysing electronic medical records (EMR) of ovarian cancer patients who received Olaparib in China from August 2018 to June 2023, documented in the National Cancer Information Database (NCID).