Peripheral facial palsy (PFP) may be the only sign of Lyme borreliosis in children. A literature study prompted by three children with PFP showed that a positive test for Borrelia burgdorferi antibodies in the blood or cerebrospinal fluid in combination with pleocytosis in the cerebrospinal fluid makes a diagnosis of Lyme borreliosis extremely probable. At least half of the children with PFP as a result of Lyme borreliosis show other signs or symptoms suggesting this disease. No data are available on the prevalence of Lyme borreliosis among children with PFP in the Netherlands; in adults, however, the prevalence is very low. Therefore, assuming a similar low prevalence in children with PFP, the predictive value of serological testing in children may be limited, in which case serological screening is not useful. Moreover, treatment with antibiotics does not seem to improve the prognosis of PFP significantly. Based on these data, serological testing and lumbar puncture is justified only in children with PFP associated with other signs or symptoms of Lyme borreliosis, such as bilaterality of the PFP, signs of meningeal irritation, a recent history of erythema migrans, arthritis or a recent tick bite.