Elevation of cardiac troponin T (cTnT) in serum reflects myocardial injury, but it was also observed in other conditions with cardiac injury including acute ischemic stroke. The objective was to identify the relationship between elevated cTnT and stroke severity, location and outcome, cTnT levels were prospectively performed in 385 patients with different subtypes of acute ischemic stroke admitted in NICU within 72 hours of onset, as TOAST criteria. The patients were divided into two groups: an elevated cTnT (group 1) (n = 42) and a normal cTnT (group 2) (n = 343). The short-term prognosis was assessed by 30-days modified Rankin Scale responder analysis and the NIHSS. Serum cTnT levels were determined using a high sensitive troponin T assay (Roche Elecsys Troponin, Mannheim, Germany), cut-off value of 0.01 ng/ml. Statistical analysis was performed. Serum cTnT level was elevated in 10.91% (42/385) of patients, cTnT positivity on admission is an independent and powerful prognosis predictor in acute ischemic stroke. It was observed a more frequent insular lobe involvement in elevated cTnT group (17/42) (31%) than in group 2 (55/343) (16%) (p = 0.040). Stroke severity was greater in elevated cTnT group. The outcome was worse in elevated cTnT group as compared to group 2 (13/43) (30.95%) vs. (68/343) (19.82%) (p = 0.013). cTnT in acute ischemic stroke is a marker of stroke severity, of insular lobe lesion and of prognosis prediction. cTnT is a highly specific and sensitive marker of myocardial damage in acute ischemic stroke due to insular lesion that induces disturbances of autonomic balance.