Introduction. Tobacco is the main preventable cause of death worldwide. Our study aimed to determine the rote of tobacco in the occurrence of non-communicable diseases (NCDs). Methods. We conducted a retrospective study including all NCDs patients during 2015-2016. NCDs include cardiovascular diseases (CVD), chronic respiratory diseases (CRD), cancers (CS) and diabetes mellitus (DM). Results. We identified 3643 cases of NCDs (43%) among 8478 hospitalizations, all diseases combined. Active smoking was found in 1076 cases (29.5%). Among the NCDs groups, CVD was the most common (65%). Tobacco was significantly associated with CVD (P<0.001), CRD (P=0.002), bronchopulmonary CS (P<0.001), haematological malignancy (P=0.023), and DM (P<0.001). Multivariate analysis performing binary logistic regression revealed that tobacco was an independent factor associated with CVD (OR =2.6, P<0.001), CRD (OR = 1.5, P<0.001), bronchopulmonary CS (OR=1.8, P=0.013) and DM (OR = 3.6, P<0.001). Conclusion. Active smoking was a major risk factor in the occurrence of NCDs. Thus, smoking cessation represents the cornerstone for preventing the spread of these diseases, especially in countries with limited resources. (C) 2018 SPLF. Published by Elsevier Masson SAS. All rights reserved.