ABSTRACT: BACKGROUND: We have recently published some work on CEA levels in hookah (also called narghile, shisha elsewhere) and cigarette smokers. Hookah smokers had higher levels of CEA than non-smokers although mean levels were low compared to cigarette smokers. However some of them were also users of other tobacco products (cigarettes, bidis, etc.). OBJECTIVES: To find serum CEA levels in ever/exclusive hookah smokers, i.e. those who smoked only hookah (no cigarettes, bidis, etc.), prepared between 1 and 4 times a day with a quantity of up to 120 g of a tobacco-molasses mixture each (i.e. the tobacco weight equivalent of up to 60 cigarettes of 1 g each) and consumed in 1 to 8 sessions. METHODS: Enhanced chemiluminescent immunometric technique was applied to measure CEA levels in serum samples from 59 exclusive male smokers with age ranging from 20-80 years (mean = 58.8 +/- 14.7 years) and 8-65 years of smoking (mean = 37.7 +/- 16.8). 36 non-smokers served as controls. Subjects were divided into 3 groups according to the number of preparations; the number of sessions and the total daily smoking time: Light (1; 1; </= 20 minutes); Medium (1-3; 1-3; >20 min to </= 2 hrs) and Heavy smokers (2-4; 3-8; >2 hrs to </= 6 hrs). Because of the nature of distribution of CEA levels among our individuals, Wilcoxon's rank sum two-sample test was applied to compare the variables. RESULTS: The overall CEA levels in exclusive hookah smokers (mean: 3.58 +/- 2.61 ng/ml; n = 59) were not significantly different (p </= 0.0937) from the levels in non-smokers (2.35 +/- 0.71 ng/ml). Mean levels in light, medium and heavy smokers were: 1.06 +/- 0.492 ng/ml (n = 5); 2.52 +/- 1.15 ng/ml (n = 28) and 5.11 +/- 3.08 ng/ml (n = 26) respectively. The levels in medium smokers and non-smokers were also not significantly different (p </= 0.9138). In heavy smokers, the CEA levels were significantly higher than in non-smokers (p </= 0.0001567). CONCLUSION: Overall CEA levels in exclusive hookah smokers were low compared to cigarette smokers. However, heavy hookah smoking substantially raises CEA levels. Low-nitrosamines smokeless tobacco of the SNUS Swedish type could be envisaged as an alternative to smoking for this category of users and also, in a broad harm reduction perspective, to the prevalent low-quality moist snuff called naswar.