Introduction: Insomnia is a risk factor for relapse in alcohol-dependence. Many conditions contribute to the severity of insomnia, including smoking. The aim of this study was to assess the association between parameters of tobacco smoking and the severity of insomnia after controlling for other correlates of insomnia in alcohol-dependent patients. Material and methods: In the study included 386 patient participants. Standardised tools were used to assess tobacco dependence (FTND), sleep (AIS and SDQ-7), alcohol dependence and consumption (MAST, TFLB), psychiatric symptoms (BSI), social support and impulsivity. Results: Current smokers constituted 79% of alcohol dependent patients. Most of them were tobacco-dependent (mean +/- SD FTND score: 6.12 +/- 2.09); 62% of participants reported insomnia (AIS). The multivariate regression analysis revealed that the severity of psychiatric symptoms (BSI, beta = 0.422, p < 0.0005), severity of tobacco dependence (FTND, beta = 0.140, p = 0.013) and intensity of drinking (TLFB, beta = 0.123, p = 0.034) predicted the severity of insomnia in alcohol-dependent subjects. Discussion: Our findings suggest that smoking is significantly associated with insomnia severity in alcohol-dependent individuals. Some alcohol dependence treatment programmes include tobacco-dependence interventions, but they are not obligatory. Tobacco dependence as well as the severity of psychiatric symptoms and recent drinking consumption were independent predictors of insomnia severity in alcohol-dependent patients, which should be taken into consideration in determining addiction treatment goals. Conclusions: Our results may implicate that addressing the issue of nicotine use during alcohol-dependence programmes might have positive influence on alcohol treatment outcomes.