Objective: To evaluate the prognostic value of lymphocyte-to-monocyte ratio (LMR) in angioimmunoblastic T cell lymphoma (AITL). Methods: Data of 64 patients diagnosed as AITL at the First Affiliated Hospital of Nanjing Medical University between June 2009 and July 2017, were analyzed retrospectively. Receiver Operator Characteristic (ROC) curve was used to calculate the cutoff value of LMR to divide this cohort of patients into high and low LMR groups. Characteristics between groups were compared by Pearson Chi-square or Fisher exact tests. Kaplan-Meier method and Cox regression were performed to probe prognostic factors associated with progression-free survival (PFS) and overall survival (OS). Results: A total of 64 cases [39 cases male and 25 ones female with the median age of 63 (29-89) years old] were enrolled. The cutoff value of LMR was 3.07. Patients with low LMR showed inferior PFS (9 months vs 13 months, P=0.044) and OS (16 months vs not reached, P=0.014), respectively than those without low LMR during a median follow-up of 33 months (5 to 103 months). Multivariate analysis showed that low LMR was an independent prognostic factor associated with poor outcomes (HR=0.48, 95% CI 0.26-0.92 for PFS, P=0.027; HR=0.38, 95% CI 0.18-0.82 for OS, P=0.013, respectively). Subgroup analysis showed that patients with low LMR and under the situation of high score of Prognostic Index for peripheral T-cell lymphoma, Unspecified (PIT) (2-4) had shorter PFS and OS (P=0.013 and P=0.031, respectively). But in low score of PIT (0-1) group, low LMR seemed to play almost no effects on PFS and OS (P=0.949 and P=0.238, respectively). Conclusions: The disease risk status of patients could be initially assessed according to PIT score and LMR level. Low LMR was demonstrated to be able to predict poor outcome in AITL.