Objective To investigate the prognostic value of preoperative plasma fibrinogen (FIB) combined with lymphocyte-to-monocyte ratio (LMR) in predicting the prognosis of patients with esophageal squamous cell carcinoma (ESCC). Methods A retrospective analysis was conducted on ESCC patients who underwent esophagectomy in the Affiliated Lihuili Hospital of Ningbo University from 2015 to 2018. Based on the cut-off values of preoperative FIB and LMR, the F-LMR scoring system was constructed, and patients were divided into three groups according to the F-LMR score. Kaplan-Meier analysis was used to assess 5-year overall survival (OS) and 5-year progression free survival (PFS), and univariate and multivariate Cox regression analyses were performed to identify prognostic factors. Results Finally 260 patients were collected, including 237 males and 23 females, with a median age of 64 years (IQR: 59-70). The 5-year OS rates for patients with F-LMR score of 0, 1, and 2 were 24.44%, 51.69%, and 67.31%, respectively, and the 5-year PFS rates were 15.56%, 42.37%, and 57.62%, respectively. Lower preoperative F-LMR scores were associated with worse prognosis. Multivariate analysis showed that deeper tumor invasion, presence of lymph node metastasis, larger tumor maximum diameter, and lower preoperative F-LMR score were independent risk factors for OS. Conclusion The F-LMR scoring system based on the preoperative FIB and LMR may serve as an effective tool for predicting the prognosis of patients with ESCC.