Oral cavity, being the first to feel the effects of cigarette smoke, is not spared of its consequences which can be seen on hard, as well as on soft teeth structures. The effects are manifested as those that are only aesthetic and those that can become life threatening diseases. Tar causes yellow to brown discoloration of teeth, gingiva and prosthetics. The level of discoloration correlates with the number of cigarettes smoked. Smokers have a reduced sense of taste and smell, and enhanced fetor ex ore. Inflammation and haemorrhage in smokers are less pronounced as compared to nonsmokers because of suppressed local immune response, as well as systemic activity of the secretion of adrenaline and noradrenaline. The incidence of periodontal disease is higher in smokers due to the impaired immune response, reduced number of lymphocytes and neutrophils dysfunction and impaired production of proinflammatory cytokines and immunoglobulins, causing the results of periodontitis treatment weaker. Likewise, smokers have a worse prognosis for a successful implant therapy. The increasing percentages of failure in implant therapies are the result of incorrectly predicted contraindications, which includes smoking. Carcinoma of the oral cavity, being the most dangerous change that smoking causes on the oral mucosa, is one of the 10 leading causes of death in the population. More than 80 % of people with oral cavity cancer are smokers. If the smokers are alchocol consumers too, then the risk of cancer is 100 % higher compared to non-smokers. Although the disease begins as erythroplakia, it is rarely detected at this stage and is mainly detected at an advanced stage when treatment options and prognosis of the disease is unfavourable.