There are a wide variety of neurologic (N) and psychiatric (P) manifestations of systemic lupus erythematosus (SLE) which extend beyond those identified in the current American College of Rheumatology (ACR) classification criteria for SLE. Several attempts have been made to devise a classification of NP-SLE manifestations. The most recent is the ACR nomenclature and case definitions for 19 NP lupus syndromes which currently provides the best means of a standardized approach to categorize NP events in SLE patients. Data from a number of studies has indicated a wide variability in the prevalence of the 19 NP syndromes. On the basis of these findings and utilizing the guidelines provided in the case definitions for diagnosis and exclusion of confounding variables, it is proposed to examine a number of NP manifestations for possible inclusion in revised classification and diagnostic criteria for SLE.