The technique of the excretion urography of the Guinea pig is described and revealed by an X-ray picture: in a deep anaesthesia a mixture of Angiographin and normal saline solution (1:4) is infused in the v. jugularis in a velocity of one drop/s. 4-5 min after finishing the infusion the renal pelvis, the ureter and the bladder is very well represented. By using the pretended doses there is no danger of allergic reaction or hypervolaemia.