Objective: To investigate the predictive value of three preoperative inflammatory markers for the development of lymph node metastases in patients with pT1a stage penile squamous carcinoma without palpable inguinal lymph nodes.Methods: Clinical data of 103 patients with pT1a stage penile squamous carcinoma admitted to the First Affiliated Hospital of Soochow University and Taixing People's Hospital during the period from January 2012 to June 2023 were collected, and the patients were divided into lymph node metastasis and non-lymph node metastasis groups according to the presence or absence of inguinal lymph node metastasis in their postoperative pathology. Differences in age, body mass index, hypertension, diabetes mellitus, tumor diameter, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and postoperative pathological grading were compared between the two groups. Independent risk factors for lymph node metastasis were screened using univariate and multivariate logistic regression analyses. Receiver operating characteristic (ROC) curves were used to compare the predictive value of inflammatory indicators for the development of lymph node metastasis in patients with pT1a stage penile cancer and the predictive efficacy of each inflammatory indicator for lymph node metastasis after adjusting the sensitivity to 100%. Results:①There were 24 cases (23.3%) in the inguinal lymph node metastasis group and 79 cases (76.7%) in the non-lymph node metastasis group. The differences between the two groups were statistically significant in terms of NLR (P < 0.001), PLR (P = 0.035)， and LMR (P < 0.001). ②The results of the multifactorial analysis showed that NLR (P=0.045) and LMR (P=0.021) were independent risk factors for developing inguinal lymph node metastasis in pT1a stage penile cancer. ③The results of the ROC curve analysis showed that the areas under the curve of NLR, LMR, and NLR+LMR were 0.833, 0.816, and 0.835 respectively. The optimal cut-off value for NLR was 2.33/L, with a sensitivity of 95.8% and a specificity of 68.4%; for LMR, the optimal cut-off value was 3.80/L, with a sensitivity of 79.2% and a specificity of 78.5%; and for the combined NLR+LMR assay, the sensitivity was 83.3% and the specificity was 74.7%. ④When the adjusted sensitivity was 100%, the predictive specificity of NLR and LMR for inguinal lymph node metastasis in pT1a stage penile cancer was 50.6% and 2.5%, with cut-off values of 1.79/L and 11.01/L. Conclusions： NLR and LMR are independent predictors of inguinal lymph node metastasis in pT1a stage penile squamous carcinoma.NLR>2.33/L and LMR>3.80/L suggest that patients are at great risk of lymph node metastasis, and lymph node dissection is recommended to improve patients' survival.