Abstract
In this study the physical parameters of 14 X ray machines located at 14 different hospitals in Egypt were subjected to investigation. The studied parameters were tube voltage, tube current, exposure time, filtration, and exposure to the patient. The radiation exposure to the patient was measured for different classes of X ray examinations in the light of the nominal physical parameters. Selected values for the physical parameters for every class of examination have been predicted. The predicted values of the physical parameters in this study could be used for achieving a reduction in radiation exposure to patients undergoing medical X ray diagnosis in Egypt.