This review covers the approximately two-year period since our last review (A1), roughly from November 1997 through October 1999. A computer search of Chemical Abstracts provided most of the references for this review. Coverage is limited to articles that describe new developments in the theory and practice of molecular luminescence for chemical analysis in the ultravioletvisible and near-infrared region.Citations may be duplicated between sections due to articles with contents that span several topics. However, in an effort to reduce the length of this review, we have tried to limit this kind of duplication. In general, citations are limited to journal articles and usually do not include patents, proceedings, reports, and dissertations.This review is considerably shorter than previous reviews. This is because we have tried to focus on important advances of general interest and relevance to the field of analytical chemistry rather than extensions of previous advances. This reduction was done at the request of the journal editor in an attempt to significantly reduce the length of the biannual reviews. We have also expanded