Recently it has been found that the number of male cases requiring for retrograde urethrography (R.U.) is increasing in association with the rapidly extending life span in Japan. This report is directed to investigating the status quo of the various techniques used in R.U. followed by measuring the radiation dose on the physician and finaliy developing the new device to reduce unnecessary radiation dose. Manual injection of the radio-opaquee contrast medium has been employed by 92.5% out of 8,259 physicians in 67 institutions. They expose themselves as well as patients to the radation duringthe course of the examination. In most of these occasions the physician is not sufficiently protected from radiation leaving the possibility of his somatic damage. From these observations, the followings were studied : 1) Application of our newly developed protective barrier, exclusive for R.U., made of lead-impregnated acryl-resin plate (KYOW GLAS-XA). 2) Employment of the high speed screen made of rare earth metal. The results were encouraging in reducing the radiation exposure dose. In conclusion, the employment of the two methods described above is efficient in obviating unnecessary radiation exposure to the physician during R.U.