Introduction: Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disorder that has been recently reported. Its pathogenesis has been uncertain up until now. To date, it has been seen to very rarely occur during pregnancy and delivery, and there are no established guidelines for its treatment in clinical practice. Here the authors report a rare case of a 24-year-old pregnant woman with anti-NMDAR encephalitis that occurred in the third trimester. After a positive treatment response, the outcomes of both the mother and baby were satisfactory. To the best of the present authors’ knowledge, this is the first report on anti-NMDAR encephalitis occurring in the third trimester worldwide. This rare case enriches the sparse literature on anti-NMDAR encephalitis during pregnancy and could play a significant role in the diagnosis and treatment of such a disorder when seen in clinical practice. Therefore, the authors have documented their experience in dealing with such a disorder and briefly reviewed previously reported cases on this disorder and its occurrence during pregnancy.