The diagnosis and management of bad breath can be easily incorporated in routine dental care by attending dentists. This article outlines the information necessary to establish a differential diagnosis of oral malodor. This includes evaluation of medical, dental, and halitosis history. It also includes the examination of extraoral and intraoral tissues and a thorough periodontal examination. The presence of bad breath is established with organoleptic and hydrogen sulfide-monitor (Halimeter) measurements. The treatment of malodor resulting from oral overgrowth of anaerobic organisms in the oral cavity consists of mechanical and chemical reduction of the microbial flora by methods that are supported by scientific evidence.