Service quality is the most important factor in the success of health care organizations; because of their vital and important services, even very small errors can be followed by great and irreparable harm and damage. This study aimed to assess the quality of services provided in the teaching hospitals affiliated to Shiraz University of Medical Sciences in 2015. This is an applied, cross-sectional, and descriptive-analytical study conducted in 2015 in the teaching hospitals affiliated to Shiraz University of Medical Sciences. A sample of 290 inpatients with at least 2 days of admission to hospital was selected using stratified sampling proportional to size and simple random sampling methods. The results showed that there were significant negative gaps in all dimensions (P > .001), and the highest and lowest means and SD of negative gaps were related to empathy (-1.35 ± 1.4) and assurance (-0.52 ± 0.95). Moreover, the results showed that there was a significant negative correlation between the patients' age and the total mean of the patients' expectations. According to the results, the studied hospitals had not been able to meet the expectations of their patients in any of the service quality dimensions. Therefore, to improve the service quality dimensions, the authors recommend holding training courses on how to interact with patients and meet their needs, providing adequate and proper information about the diseases and their treatment for the patients, having adequate medical staff, and so on.