PURPOSE: We evaluated the usefulness of magnetic resonance spectroscopy (MRS) method to differentiate the mass-like enhancing subacute infarction from malignant gliomas. MATERIALS AND METHODS: Twenty patients (M:F =11:9, mean age: 56.1 yrs) with mass-like enhancing lesions (via an MRI) were studied. Ten of the twenty patients suffered a subacute infarction, whereas the other ten had malignant gliomas. The subacute infarctions were confirmed clinically by a follow-up MRI, while malignant gliomas were confirmed via surgical biopsies. We checked the metabolite peak intensity (Choline [Cho], Creatine [Cr], N-acetyl-aspartate [NAA]) and the metabolite ratios (Cho/Cr, NAA/Cr) of (1)H MRS data, obtained on mass-like enhancing lesion in subacute infarction and malignant glioma. RESULTS: Of the (1)H MRS confirmed, the subacute infarctions (10 cases), three metabolites were identified at peak intensity (NAA, Cho and Cr peak intensity), which decreased below the normal value, while eight of ten patients (80%) of the malignant gliomas, showed a noticeable increase in Cho peak intensity, with decreased NAA and Cr peak intensity. The Cho peak intensity was statistically different between the two groups (p < 0.05). The two groups revealed that all increased Cho/Cr ratio; however, the malignant glioma group showed an increase in Cho/Cr ratio over the subacute infarction group (p < 0.05). CONCLUSION: The MRS findings revealed that the decreased Cho level, as well as the slightly increased Cho/Cr ratio on the mass-like enhancing lesion, suggests a subacute infarction rather than a malignant glioma.