One of the most important economic activity in rural areas of Iran, especially in the north of the Country is agriculture. In the present study, considering the importance of hazelnut crop in the rural life of Amlash County, the economic and social effects of hazelnut cultivation on villages and farmers were investigated. This was descriptive-analytical research that the required information was obtained through documentary sources and field studies. The statistical population includes all hazelnut growers in 38 villages of the mountainous area, Amlash County. The sample size was determined 384 items using the Morgan standard table and was distributed among the operators using the random-quota sampling method. The results showed that the economic effects of hazelnut cultivation in the indicators of economic welfare (with an average of (3.76), economic security (3.81), and employment quality (3.72) were higher than the social effects of hazelnut cultivation in indicators of participation (with the average of 3.27) and social capital (3.40) in the study area. Expanding the area under hazelnut cultivation, government support by providing low-interest banking facilities and appropriate repayment terms, product insurance, and the construction of conversion and complementary industries are some of the most important ways to develop this activity and increase its economic and social effects in villages of Amlash County.