Bacterial vaginosis represents a unique upheaval of the complex vaginal bacterial flora with disappearance of lactobacilli and overgrowth of Gardnerella vaginalis and resident anaerobic vaginal bacteria. Little progress has occurred in identifying causal factors, although the pathophysiology of this syndrome is better understood. Although symptoms are easily recognizable, obstetric and gynecologic complications continue to increase in number. Bacterial vaginosis is far more than a nuisance infection. Problems with diagnosis continue to dominate clinical practice, although new tests have been introduced. Therapeutic options have increased, although recurrent disease remains common, and management of this common complication constitutes a major challenge.