This study was conducted to investigate whether albumin-adjusted ischemia-modified albumin index (IMA index) is more sensitive and accurate than ischemia-modified albumin (IMA) as early detection marker of ischemic stroke, and to compare IMA and IMA index in progression and non-progression of ischemic stroke. This case-control study was done at an emergency medical center of a university hospital. 52 patients with neurological symptoms were enrolled (28 Ischemic Stroke Group and 24 Non-Stroke Group). In the ROC analysis of IMA index to diagnose stroke, area under the curve (AUC) was 0.990 (cutoff value 91.4; 95% CI: 0.970-1.000; sensitivity: 96.4%; specificity 95.8%). The AUC for IMA value was 0.928 (cutoff value 98 U/ml; 95% CI 0.857-0.999; sensitivity 89.3%; specificity 88.5%). [corrected] The difference between progression (n = 12) and non-progression group (n = 16) in IMA and IMA index were statistically insignificant (p > 0.01). IMA index was more sensitive than conventional IMA value as diagnostic biomarker of stroke, however, arguable as a predictive biomarker for progression of ischemic stroke.