The aim of the study was to determine the mortality in infectious inpatients with type 2 diabetes mellitus (T2DM) compared with non-diabetic population.A retrospective study was conducted on 13,916 infectious inpatients in The First Hospital of Qinhuangdao. Diabetic types were classified using International classification of Diseases-10. Mortality records were collected.The mortality was higher in patients with T2DM than patients without T2DM (T2DM 4.3% vs non-diabetes 1.7%, χ = 59.560, P < .001). In multiple logistic regression analysis, T2DM was an independent risk factor of death in infectious inpatients (OR = 1.539, 95% CI: 1.181∼2.006, P = .001). The mortalities between those with T2DM and those without T2DM were stratified by age. The mortalities of patients with T2DM were 0.0% in ∼39 years, 0.0% in 40 to 49 years, 2.7% in 50 to 59 years, 3.1% in 60 to 69 years, 4.1% in 70 to 79 years and 8.7% in 80∼ years groups. The mortalities of patients without T2DM were 0.2% in ∼39 years, 0.1% in 40 to 49 years, 0.6% in 50 to 59 years, 1.0% in 60 to 69 years, 3.1% in 70 to 79 years and 5.9% in 80∼ years groups. T2DM was an independent risk factor of death only in 60 to 69 years groups (OR = 2.323, 95% CI: 1.234∼4.372, P = .009).The increase of mortality appears earlier in patients with T2DM. Infectious inpatients with T2DM are at increased risk of death and brings heavy economic burden to patients, society and government.