Objectives: Hemoglobin A1c (HbA1c) has been recommended for diagnosing diabetes mellitus (DM). We aimed to assess the prevalence of newly diagnosed diabetes mellitus (NDDM) in patients with intracerebral hemorrhage (ICH) using HbA1c criteria and to investigate the long-term prognosis of patients with ICH with NDDM. Materials and Methods: Data of patients with ICH without a DM history were derived from the Abnormal Glucose Regulation in Patients with Acute Stroke across China. NDDM was defined as a fasting plasma glucose (FPG) level of 7.0 mmol/L or higher, a 2-hour oral glucose tolerance test (OGTT) result of 11.1 mmol/L or higher, or an HbA1c level of 6.5% or higher. The prevalence of NDDM with different screening methods was assessed. The association between NDDM and 1-year prognosis (mortality, stroke recurrence, and poor functional outcome [modified Rankin scale score of 3-6]) was estimated. Results: There were 357 patients with ICH included in the analysis, and 131 (36.7%) were diagnosed as NDDM using the new criteria. NDDM was present in 31 (8.7%), 98 (27.5%), and 68 (19.0%) patients with ICH, based on FPG, 2-hour OGTT, and HbA1c criteria, respectively. NDDM was independently associated with 1-year poor functional outcome (odds ratio 1.93; 95% confidence interval, 1.10-3.38, P=.02). Nevertheless, NDDM showed no significant association with 1-year death and stroke recurrence (P>.05 for both). Conclusions: More than one third of patients with ICH without a history of DM were diagnosed NDDM using the new criteria. NDDM by the new criteria was an independent risk factor of poor functional outcome, but not of death and stroke recurrence at 1 year after ICH onset. (c) 2018 Published by Elsevier Inc. on behalf of National Stroke Association.