Queues are one of the worst problem in hospitals in almost all World. Patients have to wait long time even to get a small operation in hospitals in Turkey. Turkey healthcare system has recently improved, but it is still not at expected level. The quantity oriented healthcare services meaning caring more patients are not good at meeting quality parameters of healthcare services. The private sector partly subsidized by governments is more profit oriented and its share has been increasing. The quality of care can be increased by low waiting and better performance of doctors. In this study, the queuing theory applications are applied two big hospitals in Istanbul during 2013-2014 years by measuring waiting time and services time and systems during different times in six months. It is found that the performance of doctors are not at expected level when total utilization is considered. Waiting long time in queues is ignored by hospitals and these long queues create high stress over patients especially at public hospitals. Patient categorization based on appointments such as scheduled patients, checking patients, urgent patients, priority patients and new patients of day, serving different patients at district time of day, combining system of all hospitals in the same city for scheduling of surgery and other operations, decreasing waiting queues and workload on doctors can help to improve the current healthcare system.