The study reports on the clinical features of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis in patients aged 18 years or younger. Over an 8-month period, 81 patients with anti-NMDAR encephalitis were identified, with 32 (40%) being ≤18 years old. The youngest patient was 23 months old, and the median age was 14 years. The frequency of ovarian teratomas was significantly higher in women >18 years old (56%) compared to girls ≤18 years old (31%) and girls ≤14 years old (9%). Behavioral and personality changes were the most common initial symptoms, followed by seizures, sleep dysfunction, dyskinesias, and speech reduction. On admission, severe speech deficits were observed in 53% of patients. Common neurological complications included seizures (77%), stereotyped movements (84%), autonomic instability (86%), and hypoventilation (23%). Responses to immunotherapy were variable and slow. Overall, 74% of patients achieved full or substantial recovery after immunotherapy or tumor removal. Neurological relapses occurred in 25% of patients, with a higher rate of full recovery in those who had a teratoma removed (5/8) compared to those without (4/23; p = 0.03). The study highlights that anti-NMDAR encephalitis is increasingly recognized in children, with a lower likelihood of tumor association in younger patients. Behavioral and speech problems, seizures, and abnormal movements are common early symptoms, but dysautonomia and hypoventilation are less frequent or severe in children compared to adults.The study reports on the clinical features of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis in patients aged 18 years or younger. Over an 8-month period, 81 patients with anti-NMDAR encephalitis were identified, with 32 (40%) being ≤18 years old. The youngest patient was 23 months old, and the median age was 14 years. The frequency of ovarian teratomas was significantly higher in women >18 years old (56%) compared to girls ≤18 years old (31%) and girls ≤14 years old (9%). Behavioral and personality changes were the most common initial symptoms, followed by seizures, sleep dysfunction, dyskinesias, and speech reduction. On admission, severe speech deficits were observed in 53% of patients. Common neurological complications included seizures (77%), stereotyped movements (84%), autonomic instability (86%), and hypoventilation (23%). Responses to immunotherapy were variable and slow. Overall, 74% of patients achieved full or substantial recovery after immunotherapy or tumor removal. Neurological relapses occurred in 25% of patients, with a higher rate of full recovery in those who had a teratoma removed (5/8) compared to those without (4/23; p = 0.03). The study highlights that anti-NMDAR encephalitis is increasingly recognized in children, with a lower likelihood of tumor association in younger patients. Behavioral and speech problems, seizures, and abnormal movements are common early symptoms, but dysautonomia and hypoventilation are less frequent or severe in children compared to adults.