Bad breath, also known as halitosis, is a common concern for millions of people. Yet there is almost no reliable way for people to properly assess their breath odor. While many develop faulty perceptions about having bad breath that affect their entire lives, others who have halitosis are unaware of their condition.The authors discuss the issues affecting self-perception of breath odor in patients who complain of halitosis, as well as in a more general, "noncomplaining" population. The article presents self-perception of breath odor as a multifactorial, psychophysiological issue that is related closely to one's body image and psychopathological profile.Based on their data, the authors suggest that every patient has a breath odor self-image. This self-image ranges from little or no distortion to severe psychopathology. Because treating patients with a specific complaint of oral malodor primarily is the responsibility of the dental practitioner, several treatment approaches are outlined: collecting odor samples from the mouth to increase objectivity, involving a confidant in diagnosis and follow-up, corroborating odor judges' scores with objective measurements, increasing the patient's sense of control over the problem and obtaining guidance from mental health professionals, when necessary.Dentists increasingly are being called on to help patients with complaints of bad breath. In diagnosing and treating such cases, dentists should consider psychological and physiological factors.