Content Summary : The Quality Stan- dards Subcommittee (QSS) develops scientificallysound, clinically relevant practice parameters to aidin the practice of neurology. This article addressesthe use of antibiotic treatments in patients with ner-vous system Lyme disease and post-Lyme syn-drome. These recommendations address the needsof medical providers caring for patients with theseconditions. Lyme disease is a multisystem infectious disease caused by the tick-borne spirochete Borrelia burg-dorferi, which frequently affects the nervous sys-tem. Published guidelines are available to assist inthe diagnosis of nervous system Lyme disease, 1 and for treatment of Lyme disease in general. 2 However, there continues to be considerable controversy anduncertainty about the best approach to treatment ofneuroborreliosis. In the United States, Lyme diseaseaffecting the nervous system is generally treated with parenteral antibiotics, although several Euro-pean studies have demonstrated comparable effi-cacy with oral doxycycline, a drug that achievesadequate levels in the nervous system. Duration oftreatment varies widely, with published recommenda-tions ranging up to 4 weeks, despite a lack of compel-ling data supporting courses longer than 2 weeks.Some practitioners treat with combinations of antimi-crobials for many months, despite an absence of datato indicate this is rational or effective. Finally, there is alack of clarity as to which syndromes associated withLyme disease reflect nervous system infection, whichare consequences of infection outside the nervous sys-tem, and which are postinfectious.