To explore the MRI imaging features and causes of misdiagnosis analysis of primary central nervous system lymphoma (PCNSL) in non-HIV individuals.Methods Sixteen patients with normal immune function of PCNSL confirmed by histopathology and related auxiliary examinations in Sichuan Provincial People's Hospital from August 2013 to August 2021 were selected. Their MRI findings were retrospectively analyzed. Eight patients which were correctly diagnosed at first diagnosis were selected as the experimental group, and 8 patients which were misdiagnosed were selected as the control group. The location, number, signal, type of enhancement, peritumoral edema, hemorrhage and necrosis of all the lesions were compared. Results Out of the 16 patients, 11 cases (68.8%) had single lesions, and 5 cases (31.2%) had multiple lesions. A total of 27 lesions of all the patients were included, 21 of which were supratentorial (77.8%), 5 of which were supratentorial (18.5%), and 1 of which was both involved (3.7%). All lesions (100%) showed significant enhancement, among which 14 lesions (51.9%) showed significant uniform enhancement and 13 lesions (48.1%) with uneven enhancement. 20 lesions (74.1%) were surrounded by moderate or higher edema around the lesion. 4 patients (25%) had hemorrhage, and 4 patients (25%) had necrosis. PCNSL in non-HIV individuals in the two groups showed statistically significant differences in the type of enhancement, bleeding grade and incidence of necrosis (P＜0.05). Conclusion PCNSL in non-HIV individuals often does not have typical imaging features of MRI. Uneven enhancement of foci, combined with hemorrhage and necrosis may be the main cause of misdiagnosis