The purpose of this study was investigation of East Azerbaijan researchers and extension agents’ view about the role of extension services on agricultural development. The methodology was descriptive-correlation which is carried out by survey method. In this study, the sample population was 335 people including all researchers and extension agents working in the agricultural sector. To assess the reliability of the questionnaire, Cronbach's alpha coefficient was used and level over 0.75 for all sections of the questionnaire was measured. Its validity was established asking for the help from the technical experts. Results showed that the agricultural extension is an undeniable necessity in the agricultural development the effects of which has been positive and significant in the major variables of the agricultural development. The shortcomings are not due to the nature of extension rather they are because of improper execution, lack of support and similar reasons. The reduction of pest damage, improvement of the social status, contribution to boost handicrafts, acceptance of product insurance, recommendations for land leveling, creation of sale cooperation, awareness raising of the market, use of modern irrigation methods and several factors else was those extension role factors that the respondents agreed upon.