Introduction: Major consideration on hospital emergency services had been taken into account in recent years. This study is aimed to analyze contributory factors of clients' satisfaction in services provided in emergency unit of selected hospitals affiliated with Tehran and Shahid Beheshti University of  Medical Sciences.

Materials and Methods: This is a descriptive-analytical and cross-sectional study. 768 clients of emergency departments of selected hospitals had been chosen during last year as  samples . 3 general and 3 specialized hospitals had been chosen randomly among total hospitals affiliated with mentioned two universities . A questionnaire consisted of  54 questions in 2 sections had been used for data collection . Reliability and validity were confirmed by professors and 50-sample pilot study respectively. The alpha-cronbach was calculated at 0.87.Responsible rate had been determined at 97.66 % . The data had been analyzed by independent sample t-test, simple linear regression and linear multi-regression.

Results: The demographic characteristics of attendants were as follows: 57.3% women, 56.8%  over  45 years old , 63.1%  social insurance coverage, 92.7% urban residents , 56%  married, 58.7%  low education ( below high school level) and 68.4%  complementary insurance coverage. Clients had to pay more  for services provided by Shahid Beheshti University. Moreover, majority of the clients paid  their  expenditures by out-of-pocket and insurance. Clients were more satisfied with admission unit ,  gaurds, physicians, nursing cadre and environment provided by hospitals of Tehran university. On the other hand , in terms of management , clients were more satisfied with management approach provided by hospitals of Shahid Beheshti university . Totally , women , elderly people , urban residents , individuals who visited physicians out of referral system and also ones who came during physician presence felt more satisfaction .Generally , patients were more satisfied with services delivered by hospital affiliated  with Tehran university .   

Conclusion: Evaluating viewpoints of patients about quality of services result in promoting current trends of providing services.