Halitosis (bad breath) applies to according to various authors--even 25-50% of the population. Volatile sulfur compounds are frequently encountered in the exhaled air. The article presents the most common causes of halitosis. It is believed that approximately 80-90% of the causes of halitosis are located in the head area (mouth, ear, nose, throat), whereas the remaining cases correspond to systemic illness, such as of the stomach and lung, certain medications or food. This paper describes different means to assess halitosis, which can be helpful in determining the diagnosis. The article describes ways to treat the symptoms and causes of halitosis associated with oral cavity. In patients who have had another source of halitosis, additional diagnostic procedures and appropriate treatment must be performed. Given the prevalence of the problem of the malodour and its impact on the quality of everyday life, halitosis is a phenomenon that should not be underestimated. The causes need to be detected and an appropriate therapy must be performed. Patients with diagnosed halitophobia should be directed to appropriate specialists.