Objective: This study was undertaken to assess patients' response to their treatment at a multidisciplinary oral malodor clinic. Method and materials: In 4 years, a multidisciplinary breath odor clinic in Belgium examined 406 patients. The team consisted of an ear, nose, and throat specialist, a periodontologist, occasionally a specialist in internal medicine, and, more recently a psychiatrist. After the initial visit, each patient was scheduled for a follow-up appointment 2 to 6 months later; however, only 143 patients (35%) showed up for this control visit. The remaining 65% of the patients answered a mailed questionnaire. Results: About half of the patients who returned no longer had complaints, white 17% reported no improvement. This group was characterized by imaginary bad breath and manifest psychologic problems. There was also disbelief of their eure, although clinical examination (organoleptic evaluation and volatile sulfide measurement by means ofa portable monitor) did not reveal any oral malodor. Some also insufficiently performed the recommended oral hygiene measures (tongue brushing and interdental cleaning). Most of the patients who returned the questionnaire were disappointed by the Suggestion that their halitosis was the result of insufficient oral hygiene. Conclusion: Better education ofboth the public and dental Professionals as to the most frequent cause of halitosis, insufficient oral hygiene, might elevate the level of compliance by patients. Keywords: follow-up, Halimeter, halitosis, oral malodor, questionnaire, volatile sulfur compounds