OBJECTIVES The objective of the present study was to investigate the influence of smoking on vertical periodontal bone loss over 10 years. MATERIAL AND METHODS The study base consisted of a population that was examined on two occasions with a 10-year interval, including 91 individuals, 24 smokers, 24 former smokers, and 43 non-smokers. The assessment of vertical bone loss was based on full sets of intra-oral radiographs from both time points. The severity of vertical bone loss was expressed as the proportion of proximal sites with vertical defects per person. RESULTS The 10-year increase in the proportion of vertical defects was statistically significant in all groups (p<0.001) and, in addition, significantly associated with smoking (p<0.05). In particular, the difference between smokers and non-smokers was significant (p<0.01) whereas former smokers did not differ from non-smokers. Moreover, the 10-year vertical bone loss was significantly greater in heavy exposure smokers than in light exposure smokers suggesting an exposure-response effect (p<0.01). Compared with non-smokers the unadjusted 10-year relative risk was 2.3-fold increased in light exposure smokers and 5.3-fold increased in heavy exposure smokers (p<0.05). CONCLUSIONS The present observations indicate a significant long-term influence of smoking on vertical periodontal bone loss, yielding additional evidence that smoking is a risk factor for periodontal bone loss.