Background. Severe periodontitis leading to tooth loss is found in 5-15% of most populations worldwide. Aim. The applicability of salivary β -hexosaminidase ( β -HEX A%, percentage of β -HEX A isoenzyme to total β -HEX) and β -HEX B% ( β -HEX B/ β -HEX) indexes was investigated as a possible marker of periodontitis. Methods. Thirty three alcohol-dependent smokers (AS) and 32 healthy controls (C) were enrolled in the study. The activity of β -HEX was measured spectrophotometrically. Results. β -HEX A% was significantly higher and β -HEX B% was lower in AS than in C group. We found a significant correlation between β -HEX A% and gingival index (GI) and an inverse correlation between β -HEX A% and salivary flow (SF), in all groups. Salivary β -HEX A% index in smoking alcoholics at 0.23 had excellent sensitivity (96%) and specificity (91%); the AUC for β -HEX A% was high (0.937). There were no correlations between amount/duration-time of alcohol drinking/smoking and β -HEX A% or β -HEX B%. We found significant correlations between the time period of denture wearing and GI, papilla bleeding index (PBI), and decayed missing filled teeth index (DMFT) and between GI and the amount of smoked cigarettes per day. Conclusion. Bad periodontal state was most likely due to the nicotine dependence. Salivary β -HEX A% is a promising excellent marker for the diagnosis of periodontitis.