The main purpose of this research is to evaluate the effectiveness of internal controls in the financial and economic complex of a government institution. In terms of methodology, this research is descriptive, its data collection tool is a questionnaire, and in terms of purpose, it is applied. The research period includes the examination of financial and economic internal controls in the three-year period ending in the fiscal years 2014, 2015, and 2016. The geographical scope of the research is financial and economic complexes, and the statistical population consists of officials, managers, and financial and economic experts. The questionnaire questions are prepared based on the research model in five dimensions of internal control as follows. The questionnaire questions are prepared based on the new COSO internal control model (2013) within the framework of three objectives, five components, seventeen related principles, and 87 points of focus, and the obtained results are as follows: In response to question one, respondents confirmed that an effective control environment in the financial and economic complex of a government institution has been formed at an acceptable level. In response to question two, respondents confirm the effectiveness of control activities in the financial and economic complex of a government institution; in response to question three, respondents confirm that there is an appropriate mechanism regarding the effectiveness of risk assessment in the financial and economic complex of a government institution. In response to question fourth, respondents confirm the effectiveness of information and communication activities in the financial and economic complex of a government institution, and in response to question fifth, respondents confirm the effectiveness of monitoring activities in the financial and economic complex of a government institution. Finally, suggestions for improving the effectiveness of internal control in the financial and economic complex of a government institution were presented. Also, suggestions were provided for researchers who intend to work in this field in the future.