Objective: To investigate the predictive value of platelet-to-lymphocyte ratio (PLR), red blood cell distribution width to platelet count ratio (RPR) and systemic immune inflammation index (SII) in the staging and postoperative recurrence of ovarian endometrial cysts. Methods: Retrospective analysis was made on the clinical data of patients who underwent laparoscopic surgery for ovarian cysts in the Affiliated Hospital of Qingdao University from January 2018 to January 2020. The patients with ovarian endometriosis cyst confirmed by pathology after surgery were the observation group (n=350), and the patients with other benign ovarian cyst were the control group (n=150). The preoperative platelet count, platelet distribution width, absolute number of neutrophils, lymphocyte absolute number, absolute number of monocytes, red blood cell distribution width, and serum cancer antigen 125 (CA125) of the patients in two groups were recorded, and PLR, neutrophil-to-lymphocyte ratio (NLR), RPR, SII, and systemic inflammation response index (SIRI) were calculated and analyzed. The general data of all patients and the follow-up data within 2 years after the operation of the observation group were statistically recorded to evaluate the diagnostic value of PLR, RPR and SII for ovarian endometrial cyst, and the predictive value of staging and recurrence within 2 years after the operation. Results: PLR, NLR, SII (median: 147.53, 1.86, and 488.70 respectively) and CA125 (median: 59.41 kU/L) in the observation group were significantly higher than those in the control group, while RPR (median: 0.16) was lower than that in the control group, with significant differences (all P<0.01). There was no significant difference in SIRI between the two groups (P>0.05). The PLR and SII (median: 122.73, 345.00) of the observation group at stage Ⅲ and Ⅳ were higher than those of patients at stage Ⅰ and Ⅱ, and the RPR was lower than that of patients with stage Ⅰ and Ⅱ, with significant differences (all P<0.001). The PLR, NLR, SII, SIRI (median: 179.63, 2.75, 762.96, and 1.06 respectively) and CA125 (median: 108.83 kU/L) in patients with recurrence were significantly higher than those in patients without recurrence 2 years after the operation, and the differences were statistically significant (all P<0.001). The area under curve (AUC) of CA125 in the diagnosis of ovarian endometriosis cyst was 0.951, the sensitivity was 85.7%, and the specificity was 93.0%, which were higher than those of PLR and SII; the AUC of PLR+SII+CA125 in the diagnosis of ovarian endometriosis cyst was 0.952. The AUC of RPR predicting the stage of ovarian endometriosis cyst was 0.713, higher than PLR and SII, lower than CA125; the AUC of RPR+SII+CA125 in predicting the stage of ovarian endometriotic cyst was 0.825, with sensitivity of 68.7% and specificity of 85.7%. The AUC predicted by SII for recurrence of ovarian endometriotic cyst within 2 years after the operation was 0.803, higher than NLR, PLR, SIRI and CA125; the AUC of PLR+SII+CA125, sensitivity, specificity was 0.813, 81.5% and 73.0%, higher than SII. Conclusion: PLR, RPR and SII are related to the staging of ovarian endometriotic cyst, and SII has a certain predictive value for the recurrence of ovarian endometriotic cyst after surgery.