Aims: The aim of this study was to investigate the frequency of diabetes mellitus (DM) among cirrhotic inpatients with different etiologies and the impact of DM on the prognosis of these patients. Methods: A retrospective study of the association between DM and cirrhosis was performed on 672 cirrhotic inpatients at the First Affiliated Hospital of Anhui Medical University from January 1, 2012 to March 1, 2013. Data were assessed using SPSS 20.0. Results: The DM prevalences involving different etiologies were 45.08%, 40.43%, 42.85%, 41.67%, and 25.56% among 672 patients with alcoholic cirrhosis, cryptogenic cirrhosis, schistosomiasis, chronic hepatitis C, and chronic hepatitis B, respectively. Multivariate analysis indicated that relative to non-diabetic patients, patients with DM were older (OR 2.83, 95% CI 2.78 -2.87, p < 0.001), had higher white blood cell levels (OR 3.01, 95% CI 2.83 -3.22, p = 0.001) and were more frequently Child-Pugh class C (OR 1.28, 95% CI 1.14 -1.55, p < 0.001); these differences were also statistically significant in univariate analysis. Univariate analysis suggested that the presence of DM was associated with a higher international normalized ratio (p = 0.013), a higher incidence of hepatic encephalopathy (p = 0.014), and a more frequent incidence of spontaneous bacterial peritonitis (p < 0.001). Conclusion: DM is extremely common among cirrhotic patients and is particularly prevalent among alcoholic cirrhosis patients in the examined region of China. The presence of DM in cirrhotic patients was strongly associated with an elevated Child-Pugh score and an accelerated progression of cirrhosis.