There are many methods and varied protocols for examining halitosis. Chemical and enzymatic tests determine the presence of bacterial species and their metabolic products or enzymes in the mouth, while halitometers precisely quantify gases but not halitosis itself. Examinations by the human nose (ie, self assessment, feedback from others, or organoleptic test by an examiner) directly target halitosis, however organoleptic examination alone is insufficient for a definitive diagnosis when the individual has no complaints about halitosis. The underlying reasons why patients seek consultation concerning halitosis are usually based on their own assessment and the opinion of others, even if those assessments are not correlated with oral odorous gas measurements. This article seeks to summarize findings and review methods of examining halitosis to determine their usefulness.