Objective of this thesis is to find out relative importance of website success factors in selecting the most preferred e-recruitment website by identifying different relative importance of each website success factors and priority of alternative websites across e-recruitment domains in Iran. This study is concerned with users of two e-recruitment websites in Iran, www.irantalent.com, and, www.agahjobs.com. The mechanics of a website is based on a literature surrounding information system success and service success. Updated Delone and McLean IS Success Model is one of the highly cited models: which concerns both IS and Service quality as an antecedent of website success. Therefore, this model that can be adapted to measurement challenges of new e-commerce world is chosen as framework for investigating e-recruitment website success. There are feedback loops between IS success variables in Updated Delone and McLean IS success model, so that this model does not have specifying levels as in a hierarchy. Therefore to identify relative importance of different success variable and to rank alternative websites, Updated D&M IS Success Model is extended through Analytic Network Process (ANP) approach. A 9 scale internet mediated questionnaire was designed and sent to 383 individuals for pair-wise comparisons (http://www.irexpert.ir/webforms/quest/quest1.aspx). Results indicate that Irantalent.com is highly preferred to Agahjobs.com with respect to all success measures in the Updated Delone and McLean IS Success model. Moreover, relative importance of success measures based on their influence on interrelated measures was found. The findings of this thesis provide decision makers of e-recruitment companies with useful insights to enhance their website quality.