© 2016 IEEE.The operating rooms are known as clean rooms because it must have the high quality air without the dust and the particles. In the clean room, the dust that is sourced from both the personnel and the patient and the machines, causes the risk of infection. By using the temiz-hava system, it is seen that the percent of infection risk decreases. But, this clean air system must be controlled by using the method of 'the clean room classification'. The classification of the clean room is determined by the international standard of particle measurements. The main criteria for the classification of clean rooms is particle dimension, particle concentration, measurement points and measurement repetition. By using nonstandard particle measurements, the true classification is not possible because all measurements are taken only from the filters and the main criterias are not considered. The purpose of this study was to develope a standard particle measurement procedure by using measures in accordance with standard, and to achieve standardization for quality studies. In this study, the particles (0.1μm, 0.2μm, 0.3μm, 0.5μm, 1μm, 5μm and 10μm) in the operating rooms of Istanbul Medical Faculty in Istanbul University hospitals were measured by using a particle measurement device in accordance with ISO 14644 and they were interpreted in accordance with the same standard. During the study, a particle measurement procedure was established for Istanbul University Hospitals. Thus, the controls were provided standardly, and the generated particle measurement procedure was applied to all hospitals in Istanbul University (ITF, CTF, Oncology, Cardiology, Dental Health Faculty).