Early neurological deterioration (END) of acute ischemic stroke may be important because it can predict clinical outcomes. We described several cases with similar clinical findings but different outcomes and analyzed the characteristics of their imaging studies. We retrospectively analyzed minor stroke patients with severe arterial stenosis within 6 hours of stroke onset. We defined END as 4 or more deterioration of the National Institutes of Health Stroke Scale score. Diffusion-weighted imaging (DWI) lesions were classified as lesions of the pial artery (PI), perforating artery (PAI) and border-zone (BZ). We consecutively analyzed a total of 12 subjects in this study. The patterns of initial DWI lesions were internal BZ (50%), PI (50%), PAI (25%), and cortical BZ (16.7%). Among them, the number of subjects with END was 5, and the frequency of internal BZ on initial DWI was significantly higher in patients with END than in those without. In conclusion, the results of this study suggest that when internal BZ infarcts are detected in patients with acute minor strokes accompanied by severe arterial stenosis, close observation and careful management should be performed because END can be induced at an early stage.