The purpose of this research is to improve the effectiveness of the Information and Technology outsourcing at Tehran Municipality and tries to identify the related and effective factors on the quality of the Information and Technology outsourcing in order to attain the mentioned goal. This is a descriptive survey research and the statistical sample size is obtained from 164 questionnaires and a new model with the following aspects has been proposed after the literature review and evaluation of several outsourcing models: The successful contracts (successfully completed contracts, The level of knowledge transfer, Efficiency of the Management System, Product Conformity, Business Model, Quality of the Project Risk Management , Information Security Fulfillment, Customer confidence in the outsourced services . Results of the binomial test indicate that except “Successful Contracts” and “Efficiency of Management Systems”, rest of the factors have significant relevance (relationship) with the quality of Information and Technology outsourcing at Tehran Municipality. Additionally, the findings of this research indicate that “Information Security Fulfillment” is the most influential factor on the quality of Information and Technology outsourcing at Tehran Municipality. Implementation of the Information Security Management Standards such as ISO 270001, approval and confirmation of the business model being obligatory for the start of the projects and use of the well-known standards in the Information and Technology Service Management in order to encourage transparent mutual commitments for both contract parties are some the future improvement recommendations