Adult sporadic Burkitt lymphoma (BL) is a rare subtype of lymphoma. In this retrospective study, we investigated the prognostic value of pretreatment lymphocyte to monocyte ratio (LMR) in a cohort of 62 patients. Using LMR < 2.6 as the optimal cutoff point, 24 patients (38.7 %) had LMR < 2.6. The complete response rates in high-LMR group and low-LMR group were 90.9 and 65.0 %, respectively (P = 0.019). At a median follow-up time of 41 months, the 3-year progression-free survival (PFS) rate and overall survival (OS) rates were 76 and 80 %, respectively. In a multivariate Cox regression model, it was found that the presence of bone marrow infiltration and low LMR were independently adverse prognostic factors for both PFS and OS. In the whole group, the addition of rituximab to treatment did not benefit patients significantly in PFS and OS. In subgroup analysis, in patients with high LMR, addition of rituximab can significantly improve survival outcomes (P = 0.046). In conclusion, we firstly found that low LMR (< 2.60) was an independently adverse prognostic factor in adult patients with sporadic BL. Intensive chemotherapy could cure the majority of patients in our study, and the pretreatment LMR might predict the value of rituximab in this age population.