The elastic moduli of the dense polycrystalline oxygen-bearing η-Ta2N3, a novel hard and tough high-pressure (HP) material, were measured using the laser ultrasonic technique. The bulk modulus was determined to be B0 = 281(15) GPa which is only ∼11% below that from HP compression measurements. Our value of the shear modulus G0 = 123(2) GPa is below those ones predicted theoretically for model structures. The discrepancies in G0 could be due to a substitution of an- ions and the formation of cation vacancies in η-Ta2N3. Self-healing behaviour of η-Ta2N3 by mechanical polishing was observed and confirmed by two independent experimental methods. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)