Since the implementation of customer relationship management software (CRM) is widespread, there is always concern about which of the various CRM software providers should be selected. The aim of this study is to identify and rank the factors affecting the selection of CRM software in Iranian organizations with Analytic Hierarchy Process (AHP). For this purpose, important properties and criteria of CRM software were identified through the study of literature and considered during the interview with experts. Then, hierarchical analysis questionnaire was designed on the basis of agreed criteria and was completed by experts. The collected data analysis results indicate that the features of software including functional capabilities (operational, analytical, communicational), non-functional capabilities and the features of providers of CRM software are the most important factors and should be considered by organizations. Also, functional capabilities, non-functional capabilities and the features of the software providers are respectively important. In addition, weights and priorities related to the criteria in each category were calculated.