Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis has been recently identified as a fulminant encephalopathy, presenting with a variety of symptoms including behavioral change, amnesia and seizures suggesting cortical gray matter involvement. A 42-year-old woman presented with acute-onset clinical and magnetic resonance imaging (MRI) findings indicating brainstem and diencephalon involvement. Her neuropsychological examination revealed mild frontal dysfunction with no memory impairment. Detailed diagnostic workup proved negative except for serum/cerebrospinal fluid (CSF) NMDAR-antibodies and increased activity in inguinal and pelvic lymph nodes on positron-emission tomography (PET) examination. The symptoms and MRI findings completely resolved following steroid treatment. A 38-year-old woman presented with migraine-type headache and episodes of forgetfulness. Her brain MRI and neuropsychological examination were normal and diagnostic workup was unremarkable. N-methyl-D-aspartate receptor antibodies were identified in her sera and her symptoms spontaneously resolved within few months. Our cases suggest that anti-NMDAR encephalitis might present with minimal cognitive impairment, no apparent cortical gray matter involvement, a mild clinical course and without the classical clinical features of the disease.