Objective To determine the predictive value of neutrophil to lymphocyte ratio (NLR) for microalbuminuria of type 2 diabetes mellitus (T2DM). Methods A retrospective analysis was performed on 400 T2DM inpatients admitted to the Department of Endocrinology, Hebei General Hospital from November 2020 to June 2021. Using the results of 24 hour urinary microalbumin, the patients were assigned to the normal group (n=236, 24 hour urinary microalbumin<30 mg) and the microalbuminuria group (n=164, 30 mg≤24 hour urinary microalbumin<300 mg). The general data and laboratory results were compared between two groups, binary Logistic regression analysis was conducted to assess the influencing factors for microalbuminuria in T2DM patients. The predictive value of NLR and combined diagnosis on microalbuminuria in T2DM patients was evaluated by drawing receiver operating characteristic (ROC) curve. Results The percentage of patients with advanced age and hypertension, white blood cell (WBC) count, neutrophils absolute (NEU) count, NLR, triglyceride (TG), serum creatinine (Scr) and urea nitrogen (BUN) were higher in microalbuminuria group than the normal group, but the estimated glomerular filtration rate (eGFR) and high density lipoprotein cholesterol (HDL-C) were significantly lower than that in the normal group (all P<0.05). The area under the curve (AUC) of NLR alone for predicting microalbuminuria of T2DM patients was 0.644[95%CI(0.586, 0.701)], the best cutoff value for 2.81, the sensitivity for 46.1%, and the specificity for 85.8%. The AUC obtained by NLR combined with BUN, eGFR, TG, and whether hypertension was 0.727[95%CI (0.678, 0.777)], the optimal cutoff of 0.426, the sensitivity of 59.9%, and the specificity of 74.2%.Conclusion NLR can be used as one of the clinical indicators to predict microalbuminuria of T2DM patients.