Conditions have been chosen for the decomposition of yttrium orthotantalate and the subsequent determination of yttrium and tantalum in this compound, which is used as an x-ray contrast agent. Methods are developed for the identification of yttrium and tantalum using complexation reactions. These methods have proven to be specific and can be recommended for the identification of yttrium and tantalum in the new preparation of yttrium orthotantalate 3% suspension for use in x-ray fluorography. Infrared spectroscopy can be used to confirm the identity of yttrium orthotantalate in the studied pharmacological agent.