Résumé : Background. This dissertation focuses on two major epidemics, Waterpipe (WP) and Cigarette tobacco smoking, as two considerable global public health issues. It consists of three papers that were published in international peer review journals. We aimed at evaluating the acute and chronic effects of WP and cigarette smoking on the cardiovascular and respiratory systems, as well as evaluating the patient's acceptability of shocking pictorial versus actual textual warnings on tobacco packages as an effective control intervention towards smoking cessation".Methods. In the first part of the study, patients were recruited from restaurants in Beirut and Mount Lebanon in order to evaluate the acute (after 45 minutes of waterpipe smoking or immediately following one cigarette smoking) and chronic (before the smoking session) effects on the Forced Expiratory Volume at 1 second (FEV1), Forced Expiratory Volume at 6 seconds (FEV6), FEV1/FEV6, Diastolic Blood Pressure (DBP), Systolic Blood Pressure (SBP) and heart rate (HR). The second part of the study recruited patients from 5 outpatient clinics located in 5 hospitals in Lebanon. The purpose was to evaluate the acceptability of shocking pictorial health warnings versus the actual textual warnings on packages as an effective tobacco control intervention by evaluating their impact on smoking behaviors and motivation.Results. Mean values of FEV1, FEV6, FEV1/FEV6, DBP, SBP in the acute effect of smoking WP and cigarette smokers were very close. There was a trend to significant acute variation between the three groups for DBP (p=0.05) and a significant variation for HR (p˂0.001): DBP increased in WP smokers while it decreased in cigarette smokers. However, the HR increased in both WP and cigarette smokers after the smoking session, but much more with WP. The pulmonary functions (FEV1, FEV6 and FEV1/FEV6) and the cardiovascular values (DBP, SBP and HR) were significantly associated with the following factors: duration of smoking, age at first WP and quantity of smoking. Among the 127 WP smokers, a higher effect of the shocking pictorial warnings was observed in the highly motivated group versus the lower motivated group (OR=4.47, p=0.001); indeed, a higher switching in their favorite tobacco brand was observed in the highly motivated group versus the lower group (OR=2.76, p=0.008). In addition, smokers who had chronic cough were highly motivated to quit waterpipe smoking compared to smokers without chronic cough (OR=7.24, p=0.03).Higher motivation to quit cigarette smoking was seen among male smokers versus females (OR=1.8, p=0.02), among smokers who had stopped smoking for at least 1 month during the last year due the textual warning (OR=2.79, P˂0.001), among smokers who considered very important to report health warning on cigarette packs (OR=1.92, p=0.01), among smokers who had chronic expectorations (OR=1.81, P=0.06) and among smokers who would change their favorite cigarette pack if they put shocking images on the pack (OR=1.95, p=0.004).Conclusions. WP smokers seem as affected as cigarette smokers for the pulmonary values and that acute effect of WP immediately measured after the smoking session increases DBP and SBP; however, acute effect of cigarette decreases DBP and SBP, while both cigarette and WP smoking increase HR. The reduction of most Pulmonary Function Test (PFT) values could be due to the long duration of smoking, younger age of smoking the first WP and quantity of smoking. It differs between cigarette and WP, and between chronic and acute effect of smoking. Moreover, pictorial graphic warnings are more influencing on the behavior of waterpipe smokers than textual warning. On the other hand, low dependent and highly motivated to quit cigarette smokers appeared to be more hypothetically susceptible to shocking pictorial warnings. Motivation to quit cigarette smoking was affected by sensitivity to warnings, but not to the presence of all chronic respiratory symptoms. Thus, our study provides further reasons to the policymakers in Lebanon to incorporate more tobacco labeling policies in order to help in reducing the widespread of waterpipe and cigarette tobacco smoking and in increasing the awareness concerning the health symptoms effect of smoking.