Background: Ovarian cancer (OC) is a leading cause of death from gynecologic cancers in women worldwide. Poly adenosine diphosphate ribose polymerase (PARP) inhibitors prevent the repair of single-strand breaks and generate double-strand breaks in tumor cells and have recently shown survival benefits in OC. Yet, the impact on the risk of secondary hematologic malignancies (SHM) remains uncertain. We performed a combined meta-analysis of randomized controlled trials (RCT) to determine the risk of SHM in patients with advanced OC treated with PARP inhibitors. Methods: MEDLINE, EMBASE databases and meeting abstracts from inception through January 2020 were queried. Phase III RCTs utilizing PARP inhibitors maintenance in advanced OC were eligible. Mantel-Haenszel (MH) method was used to calculate the estimated pooled risk ratio (RR) with 95% confidence interval (CI). Heterogeneity was assessed with I² and Cochran's Q- statistic. Fixed effects model was applied. Results: A total of 4,445 patients with advanced OC from seven phase III RCTs were included. The study arm used olaparib or niraparib or rucaparib or veliparib or olaparib +bevacizumab while the control arm utilized placebo or bevacizumab. Randomization ratio was 2:1 in all studies. The I² statistic for heterogeneity was 0, suggesting some heterogeneity among RCTs. The overall SHM incidence was 0.80% in PARP inhibitors group vs 0.47% in control group (RR 1.45; 95% CI: 0.68 – 3.07, P = 0.34). In patients with newly diagnosed OC (n = 3,044), the incidence was 0.59% vs 0.09% in control group (RR 2.7; 95% CI: 0.7—10.37, P = 0.15). In recurrent OC subset (n = 1,401), 1.28% were reported in both study and control arms (RR 0.96; 95% CI: 0.38-2.46, P = 0.94). SHM was noted in 1.3% in the olaparib subgroup compared to 1% in the control with RR of 1.24 (95% CI: 0.46 –3.31, P = 0.67). SHM occurred in 0.7% in the niraparib subgroup compared to 0.47% in the control with RR of 1.28 (95% CI: 0.30-5.45, P = 0.74). Conclusions: Our study demonstrated that the risk of SHM was not significantly increased in patients who received PARP inhibitors compared to control arm, despite attaining survival benefits. Further studies and long term follow up are necessary to define the actual relation and definitive incidence.