Background and aims: Owing to the limited studies and controversial evidence, the connection between diet quality and survival of patients with ovarian cancer (OC) has been indistinct. Our study intends to first investigate this topic based on Chinese diet quality scores. Methods: Our data come from an ovarian cancer follow-up study, which includes 796 patients with OC between 2015 and 2020. Three diet quality scores, including the Chinese Healthy Eating Index (CHEI), Dietary Balance Index (DBI), and Chinese Food Pagoda Score (CFPS), were calculated using a validated 111-item food frequency questionnaire. We used the Cox proportional hazards regression model to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Potential multiplicative and additive interactions were also assessed. Results: With a median follow-up time of 37.17 months (interquartile: 24.73-50.17 months), we recorded 130 deaths. According to comparisons of the highest to lowest tertile of scores, the pre-diagnosis CHEI was linked to better overall survival (OS) in patients (HR = 0.56, 95% CI: 0.36, 0.88). A dose-response relationship between CHEI and OS was also observed (HR = 0.85, 95% CI: 0.71, 1.00, per 1 standard deviation increment). However, no evidence of significant associations between DBI and CFPS with OS was observed. Additionally, significant multiplicative and additive interactions were seen in the diet quality scores (CHEI and DBI) with the body mass index and the menopausal status. Conclusions: A high CHEI was associated with an improved OS for patients with OC, while DBI and CFPS were unrelated to OC survival.