Objective <p>Conventional imaging often struggles to differentiate between primary angiitis of the central nervous system (PACNS) and intracranial tumors. This study aims to evaluate the application value of proton magnetic resonance spectroscopy (¹H-MRS) in distinguishing PACNS from intracranial tumors.</p> Methods <p>This study collected data from 10 patients with PACNS and 15 patients with intracranial tumors (10 gliomas and 5 lymphomas) confirmed by pathological biopsy. The levels of choline (Cho), creatine (Cr), and N-acetylaspartate (NAA) in the lesion areas and contralateral normal brain tissue were measured and analyzed using ¹H-MRS, and the ratios of Cho/Cr, NAA/Cr, and Cho/NAA were calculated. The diagnostic efficacy of ¹H-MRS in distinguishing PACNS from intracranial tumors was evaluated using receiver operating characteristic (ROC) curves and area under the curve (AUC).</p> Results <p>Compared to contralateral normal brain tissue, significant differences were observed in the ratios of Cho/Cr, NAA/Cr, and Cho/NAA between the lesion areas of PACNS and intracranial tumors (<i>P</i> &lt; 0.001). After correcting for the corresponding normal brain tissue spectra, the NAA/Cr ratio in PACNS lesion areas was significantly higher than in intracranial tumor lesions (0.90 vs. 0.25, <i>P</i> &lt; 0.001), and the Cho/NAA ratio was significantly lower in PACNS lesions (1.98 vs. 9.00, <i>P</i> &lt; 0.001), while the difference in Cho/Cr was not significant (1.59 vs. 1.94, <i>P</i> = 0.405). When the corrected NAA/Cr ratio was ≥ 0.71, the ROC-AUC for diagnosing PACNS was 1.00, with both specificity and sensitivity at 100%. The subgroup analysis of glioma/lymphoma yielded similar results.</p> Conclusion <p>The ratios of NAA/Cr and NAA/Cho are significantly meaningful in differentiating PACNS from intracranial tumors, and ¹H-MRS can be an effective tool for distinguishing these two conditions.</p>