Objective This study aims to investigate the impact of clinical characteristics, antibody types, timing of treatment, and tumor comorbidities on the efficacy and prognosis of patients with autoimmune encephalitis (AE), aiming to provide a reference for clinical management. Methods A retrospective analysis was conducted on the medical records of 203 AE patients admitted to the Department of Neurology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, from January 2020 to June 2025. Statistical analysis was performed on patients’ gender, age, disease course, antibody types, and tumor screening results to evaluate their impact on treatment efficacy. Additionally, the clinical assessment scale for autoimmune encephalitis (CASE) scoring system was used to assess treatment outcomes. Results A total of 203 AE patients were included in the study, in which 56.2% cases were male, a median age was 50 years, and most of the disease course was subacute (64.0%). The antibody profiles showed high heterogeneity, with N-methyl-D-aspartate receptor (NMDAR) antibodies being the most common (24.1%). Treatment outcomes revealed that an overall improvement rate is 79.8%, but the significant improvement rate was only 11.3%. The tumor comorbidity rate was 15.3%, and the efficacy of treatment in patients with tumors was slightly lower than that of the non-tumor group. Conclusions The efficacy of AE treatment is influenced by multiple factors, including antibody characteristics, timing of treatment, disease severity, and tumor comorbidities. Timely immunotherapy significantly impacts prognosis, and early diagnosis and treatment can improve clinical outcomes. Precise antibody testing and systematic tumor screening are crucial strategies for promoting the prognosis of AE patients. Future clinical management should strengthen comprehensive assessment of the above factors to achieve optimal treatment outcomes and enhance long-term prognosis.