Smoking represents the most extensively documented cause of disease ever investigated in the history of biomedical research. While regulations and public health campaigns have helped to reduce the prevalence of cigarette smoking, a significant percentage of the population still smokes tobacco. Tobacco use results in a greater risk of cancer, lung disease, and cardiovascular diseases. Other effects of tobacco use include affection of gustatory and olfactory functions. Taste and smell in humans provide an important tool for screening soluble and airborne chemicals for food selection, evaluation, and avoidance of potentially toxic compounds. In general, normal functioning of the gustatory and olfactory systems is necessary to maintain a good quality of. Deficiencies in taste and smell can cause anxiety, depression, and even nutritional deficiencies. The aim of the present investigation was to study the association between smoking and gustatory and olfactory sensation, and the possible changes in salivary volume and pH among smokers. The study was conducted on 100 individuals that were divided into two groups; smoker subjects group and a non-smokers one. Each group consisted of 50 individuals. All individuals received general clinical examination and oral examination. Subjects who suffered from or were receiving treatment for any systemic ailments were excluded. Also, those who had intraoral diseases were excluded. Salivary flow rate (ml/minute) was tested by collection of whole saliva (spitting method) for each individual at rest for ten minutes, and the salivary pH of each individual was determined using a pH meter. The results of the present study showed that the mean salivary volume was not affected by smoking at all. On the other hand, the current study revealed that the mean pH of saliva in smokers was significantly lower than that in non-smokers. Gustatory testing was performed on all participants whereas a forced choice recognition threshold procedure was applied using three drop technique. In a similar manner the olfactory function was investigated. The results of the present study showed that salty, bitter and sour sensations were affected by smoking as there was significant increase in their recognition threshold in smoker group. However, sweet did not seem to be significantly affected. On the other hand, for olfactory sensation, jasmine, mint and strawberry recognition thresholds were significantly increased in smoker group denoting the effect of smoking on olfactory sensation as well. From these results, we can support the association between smoking and taste and smell disturbance, as these results indicated that smoking has a significant effect on gustatory and olfactory functions.