Halitosis affects a large part of the population. Many of those that are affected suffer from this problem for a long time before they visit a professional halitosis clinic. Further, halitosis creates social and psychological disadvantages. Although halitosis has multifactorial origins, in nine out of ten cases the source can be found within the oral cavity. The most frequent intra-oral causes are tongue coating, gingivitis, and periodontitis, or a combination of these. A general dental practitioner is often faced with patients suffering from halitosis in her/his dental practice and therefore should be able to manage it. Using standardized strategies, a high level of treatment success can be achieved. In the literature, several methods to determine halitosis and various possibilities for treatment are described. The present review summarizes diagnostics, prevalence, and current treatments of oral halitosis.