Alcohol dependence (or alcoholism) can be treated with various drugs, including disulfiram, which blocks aldehyde dehydrogenase (ALDH). However, current treatments result in undesirable side effects. ALDH2 plays a vital role in alcohol metabolism in the liver and is associated with alcohol dependence. Artificial microRNAs (amiRNAs) are powerful biological tools used to knock down disease-related genes for mechanistic research and therapeutic applications. In the present study, we aimed to identify the effects of amiRNA knockdown of ALDH2 in the liver. Lentiviruses expressing one of four amiRNAs targeting ALDH2 (amiRNA1, amiRNA2, amiRNA3 and amiRNA4) or a negative control amiRNA (amiNC) were designed, and the knockdown efficiency of ALDH2 was measured in Hepa-1c1c7 cells. amiRNA4, one of four (ami RNA1-4) lentiviruses expressing an ALDH2 amiRNA, was injected into the tail veins of mice. Alcohol consumption was analyzed over twenty days following the injection. In addition, ALDH2 expression levels and enzyme activity in the liver were measured. ALDH2 knockdown by four amiRNAs was successively achieved in Hepa-1c1c7 cells. Voluntary alcohol consumption of mice injected with amiRNA4 decreased compared with mice injected with amiNC. ALDH2 expression in the livers of mice injected with amiRNA4 also decreased more than 2.5-fold compared with mice injected with amiNC, which indicates that ALDH2 expression in the liver and alcohol consumption were altered by ALDH2 knockdown using amiRNAs. These results suggest that amiRNAs have the potential to act as therapeutic agents for the treatment of alcoholism.