Subclinical inflammation may be involved in the pathogenesis of diabetic cardiac autonomic neuropathy (DCAN). The purpose of the study is to explore the relationship between novel inflammation biomarkers fibrinogen-albumin ratio (FAR), fibrinogen-prealbumin ratio (FPR), and DCAN in type 2 diabetes mellitus (T2DM). A total of 715 T2DM patients were enrolled in this retrospective study, divided into non-DCAN (n=565) and DCAN (n=150) groups by Ewing's test. Serum fibrinogen, albumin, prealbumin, routine inflammatory and other biochemical markers were measured. Patients with versus without DCAN had higher FAR (10.29 ± 4.83 vs 7.22 ± 2.56 g/g, P < 0.001) and FPR (2.19 ± 1.85 vs 1.43 ± 0.93 g/mg, P < 0.001). As FAR and FPR quartiles increased, the incidence of DCAN increased (Quartile 1 vs Quartile 4: 8.4 vs 42.7%, 9.6 vs 39.2%, respectively, P < 0.001), heart rate variability parameters decreased (P < 0.001); the incidence of diabetic nephropathy, retinopathy and peripheral neuropathy tended to be higher and inflammation factors were more active (P < 0.01). FAR (OR, 95% CI: 1.16, 1.08-1.25, P < 0.001) and FPR (OR, 95% CI: 1.22, 1.03-1.44, P = 0.021) were independent determinants of DCAN; the risk of DCAN increased by approximately 65% and 27% with each increase in the standard deviation (SD) of FAR (OR per SD, 95% CI: 1.65, 1.29-2.11, P < 0.001) and FPR (OR per SD, 95% CI: 1.27, 1.04-1.56, P = 0.021). FAR and FPR are independent risk factors and may influence DCAN development through inflammation.