Background: Neoadjuvant chemotherapy (NACT), followed by interval debulking surgery (IDS), is a possible approach to patients with stages IIIC and IV epithelial ovarian cancer who are most likely to have suboptimal results with upfront surgery. Delay in initiation of adjuvant chemotherapy has been associated with worse outcomes. Our study aimed to evaluate whether time from NACT to surgery (TNS) and from surgery to adjuvant chemotherapy (TSA) were associated with survival outcomes and with platinum-resistant relapse. Methods: We did a retrospective analysis of medical records from 194 patients with EOC treated with IDS at a single institution from 2007 to 2018. We calculated the median TNS and TSA and evaluated its relation to progression free survival (PFS), overall survival (OS) and time to platinum-resistant relapse (TTPR) through Kaplan-Meier and Cox regression analysis. Results: After a median follow-up of 62 months, OS was 58 months and PFS was 18 months. Most patients received at least 3 cycles of NACT (21.1% 3 cycles, 16.0% 4 cycles and 39.7% 6 cycles); and the rate of optimal cytoreduction was 75,8%. Optimal surgery was associated with survival (p < 0.001). TNS over 8 weeks and TSA over 7 weeks were associated with worse PFS (HR 1.57, 95%CI 1.07-2.31; HR 1.52, 95%CI 1.00-2.32, respectively) and OS (HR 1.83, 95%CI 1.13-2.96; HR 1.57, 95%CI 0.93-2.65, respectively) in univariate analysis but not in a multivariate analysis including residual disease as a covariate. In the subgroup of patients with residual disease < 10mm a multivariate analysis showed shorter PFS (HR 2.06, CI95% 1.16-3.66, p = 0.014) and OS (HR 2.20, CI95% 1.05-4.59, p = 0.035) for patients with TSA longer than 7 weeks. Longer TNS was associated with PFS (HR 1.66, 95%CI 1.06-2.59, p = 0.026) in univariate analysis but not in multivariate analysis. Interestingly, longer TNS was associated with shorter TTPR (65.6 vs. 35.0 months, p = 0.049) and a higher frequency of platinum resistant relapse at first relapse (48.8% versus 26.5%, p = 0.012). Conclusions: Our study provides evidence that delayed TSA is an independent prognostic factor for worse PFS and OS only in the subgroup of patients with residual disease ≤ 10mm. Longer TNS was associated with higher risk of platinum resistant relapse. One possible explanation is that NACT may select chemoresistant clones, which would have more time to grow and spread with longer intervals until surgery. Further studies are necessary to corroborate this hypothesis.