Nowadays, the adverse effects of smoking on general, oral, and dental health are reported time and again worldwide. However, evidence to quantify the effects of tobacco smoking and smoking cessation on health-related quality of life (HRQoL) and oral health-related quality of life (OHQoL) is inadequate. Accordingly, this study aimed to assess the effects of nicotine gum on HRQoL and OHQoL of cigarette smokers. This pilot study was conducted on 40 smokers, half of whom received nicotine gum. HRQoL and OHQoL were measured twice at the beginning of the study and after three months using standard versions of Short Form Health Survey (SF-12) and Oral Health Impact Profile (OHIP-5) questionnaires. T-test, Fischer's exact test, and Pearson's correlation coefficient were used to compare the participants' scores on the questionnaires. The mean age of the participants was 43.39±12.32 years. Using nicotine gum significantly increased the scores of general health (P=0.046) and physical functioning (P=0.021) domains of HRQoL in comparison with the cigarette smoking group. Moreover, using nicotine gum significantly increased the scores of the two questions about the reduced sense of taste (P<0.001) and difficulty doing usual jobs (P=0.071). Using nicotine gum was associated with the improvement of HRQoL and OHQoL to some extent. To better understand the relationship between smoking cessation and improved OHQoL, it is necessary to conduct further studies in this field.