Alcohol and smoking are a global health problem, and epidemiological studies show that ethanol and nicotine abuse influence each other's use. It has been estimated that over 83% of alcoholics smoke, and alcoholism is about 10 times more common in smokers than in non-smokers. There is a strong correlation between alcohol and nicotine addiction. People addicted to alcohol are three times more likely to smoke than the general population, and people addicted to tobacco are four times more likely to be addicted to alcohol. Analysis of possible mechanisms that determine the abusive consumption of alcohol and nicotine. Nicotine and alcohol can influence their consumption through a combination of genetic, psychosocial and neurobiological factors. Nicotine activates N-choline receptors, which in chronic smokers cause their desensitization with transformation into a non-functional state. In case of decreased nicotine concentration some N-choline receptors return to the functional state with hyperactivation of the cholinergic system and other neurotransmitter systems with the manifestation of the rebound phenomenon. It has been suggested that ethanol is an allosteric modulator of N-cholinergic receptors with increased affinity, potentiation of their nicotine activation and acceleration of the transition of cholinoreceptors into a functional state with increased nicotine consumption. These mechanisms may explain the phenomenon of increasing the frequency and quantity of cigarettes used in the state of alcohol intoxication. Nicotine and alcohol have many common targets that directly and indirectly affect the mesolimbic dopaminergic system. Alcohol and nicotine modulate the function of many membrane proteins and neuroendocrine effectors to influence inhibitory and excitatory transmission. The comorbid use of alcohol and nicotine indicates the role of two key psychopharmacological mechanisms - attraction and cross-tolerance. The strengthening of cross-attraction is revealed by the fact that alcohol and nicotine potentiate the mutually satisfying effects, manifested by increased appetite, rewarding subjective effects, consumption and increased motivation to consume the other drug. Alcohol and nicotine have a cross-tolerance effect in that nicotine reduces or blocks the sedative and intoxicating effects of alcohol, helps to mitigate the negative effects of ethanol that limit the consumption of beverages.