It was found that ischemic stroke (IS) results in decreased levels of a number of reduced forms of low molecular weight aminothiols (LMWTs). The study was aimed to assess the impact of type 2 diabetes mellitus (Т2D) on the total content, reduced forms and redox status of LMWTs in patients with IS. A total of 175 patients with IS in the internal carotid artery basin (the average age was 62 (55–69)) years) were assessed, who were admitted to the Center within the first 10–24 h since the onset of neurological disorder. The index group included 68 patients with IS and T2D (males made up 41.2%). The comparison group consisted of 107 patients with IS and stress hyperglycemia (males made up 57%), and the control group included 31 non-diabetic patients with chronic cerebrovascular disease (CCVD) (males made up 54.8%). The admission plasma levels of LMWTs were assessed by liquid chromatography in all patients. It was found, that IS in patients with T2D was associated with the rapid decrease in total cysteine (tCys), total glutathione (tGSH), total homocysteine (tHcy), reduced glutathione (rGSH), and glutathione redox status (GSH RS), along with the increase in cysteine redox status (Cys RS) and homocysteine redox status (Hcy RS). In contrast to patients with stress hyperglycemia developing during the acute period of IS, patients with T2D had lower tCys, tGSH, and tHcy levels. Thus, GSH RS of 4.06% or lower in the first 24 hours after the IS in patients with T2D was a predictor of poor functional outcome (mRS score was 3 or more 3 weeks after IS).