Background <p>The transient Headache and Neurological Deficit with cerebrospinal fluid Lymphocytosis (HaNDL) Syndrome is a rare form of primary headache, with few cases reported in children.</p> Case presentation and review <p>We report the case of a 15-year-old female with HaNDL syndrome showing paresthesia to the right side of her face and upper limbs, asthenia, dysarthria and aphasia, followed by left periorbital pulsating headache with moderate nausea, lasting about four hours. Forty-four cases of pediatric HaNDL syndrome are reported in literature (ours included), but only 25 fulfilled all diagnostic criteria according to ICHD-3. Overall, 59.1% were females. Sensory symptoms affected 71.4% of patients, followed by impaired speech (69.0%) and motor symptoms (52.4%). At CSF analysis, the mean value of white blood cells was 201.1/µl; proteinorrhachia was reported in 31 patients (70.5%). When asked, neuroimaging was negative. Symptomatic treatment was reported only in 14 patients (31.8%).</p> Conclusions <p>HaNDL is a rare self-limiting syndrome affecting both adults and children. The etiology is unknown, but autoimmune mechanisms have been proposed. HaNDL is a diagnosis of exclusion: differential diagnoses include stroke, tumors, epilepsia, neuro-infective disorders, autoimmune encephalitis, vasculitis, hemiplegic migraine and migraine with aura. Usually, HaNDL episodes last less than 3 months; therapy is symptomatic. The diagnostic work out includes CSF analysis, neuroimaging and EEG. The treatment is symptomatic, and the course is self-limiting, usually resolving within 3 months.</p>