We report an unusual case of pediatric GBS which development coincided with the development of HAV IgM (+) viral hepatitis A. From the second to the 14th day after admission to the hospital for mild jaundice of the skin and sclera in a 12-yr-old boy, the following neurological disorders have developed: absent Achilles and knee-jerk reflexes, diminished brachioradialis reflex, moderately decreased muscle power in the upper extremities and more pronounced power loss in the lower extremities. This evidence concerns the gene CD40LG and hepatitis A virus infection.