The adulteration of wine usually refers to alcohol and glycerol addition, dilution with water, and change of aroma and color by using different substitutes. In this situation the final product consumption can be an unsafe product for human health, because the added ingredients are not well controlled by authorities before processing. The purpose of the study was to find the adulterated wine samples produced in Cotesti vineyard (Vrancea County) by several wineries during the period of time of 3 years (2007, 2008 and 2009). A number of 219 wine samples were analyzed and it was found that the low quality wines are usually adulterated. It was found a decreasing in adulterated wine samples provided by Cotesti vineyard from 88.3% adulterated samples in 2007 to 48.5% adulterated in 2009. The decreasing trend of the adulterated wines during the period of three years (2007, 2008 and 2009) can be explained by the application of Romanian legislative regulations on wine quality level.