Ever - increasing changes in agricultural production systems in both developing and industrial countries in order to empowering economical specialists, asks for new management knowledge and skills. One reason of inadequate crops production in developing countries is persisting use of old traditional methods also insufficient attention to the new scientific methods. Despite significant scientific improvements in different area of farm management, still there is a considerable gap between farmers' decision making and research organizations commands and expects. Little knowledge of farmers along with insufficient attention to the farmers' role in decision making for different levels, could be held as the reasons of this gap. Although 3 milliard tones of pesticides are being consumed each year in the world, more than 40% of crops are destroyed because of the pests, so importance of the pest management is cleared. Assessing farmers' decision making in pest management of rice pest in Isfahan is the aim of this study. This study has been formed in six important townships of Isfahan in rice farming. After a questionnaire designing and a preliminary study, the quantity of samples was estimated for 170 persons. Then, the study independent and dependent variables and their reliability and validity was evaluated and totally approved. The study data as analyzed by cluster test, cross tabulations, chi squer statistic, pearson correlation coefficient, spearman, kendall tao, phi, cramer's and regression. The result showed that farmers' pest management decision making in Isfahan is low and between the Farmers' decision making in different regions there are significant differences. High effecting factors in farmer pest management decision making, allocated in Farmers' human skills. Also farming rice income, main job of rice farmers, educational levels, rice farm size, distance to province, harvesting mechanization, the level of training, the level use of media, rice Farmers' observators, level of membership in groups and labels of pesticides variables have shown positive and significant correlation with dependent variable and pesticides dealers variable have shown negative and significant correlation with Farmers' pest management decision making. The result of path analysis indicated that 74.1% of changes in independent variable in this reaserch illustrated. Key words Effecting factors, Farmers' decision making, Pest management, rice, Isfahan