Background/Objectives: Cervical cancer remains a global health burden. The loop electrosurgical excision procedure (LEEP) is effective for cervical intraepithelial neoplasia. Positive margins often complicate decisions about repeat conization. HPV testing is standard in post-treatment surveillance, but its limited specificity shows the need for additional, cost-effective biomarkers. This study evaluated whether changes in systemic inflammatory indices—platelet-to-lymphocyte ratio (PLR), systemic inflammation response index (SIRI), and systemic immune-inflammation index (SII)—can predict residual high-grade lesions after incomplete excision. Methods: This multicenter retrospective study included 125 patients who underwent repeat surgery after LEEP due to positive margins. Changes in preoperative inflammatory indices (ΔPLR, ΔSIRI, ΔSII) between the first and second procedures were analyzed by the histopathological findings of the second surgery. Group differences were assessed using the Mann–Whitney U test, and receiver operating characteristic (ROC) analysis was used to evaluate discriminatory performance. Results: Significant differences were found in ΔPLR (p = 0.032) and ΔSII (p = 0.048) between patients with and without residual high-grade lesions or invasive cancer. ΔSIRI showed borderline significance (p = 0.050). For invasive cancer alone, ΔSIRI was significantly associated with malignancy (p = 0.035). ROC analysis showed modest predictive performance (AUC ≈ 0.60). Conclusions: Dynamic changes in PLR, SIRI, and SII may be as inexpensive adjunct biomarkers to support risk stratification after incomplete LEEP and can complement HPV testing in certain clinical settings.