Magnetic materials with spinel structure exhibit rich physical phenomena originating from the interplay of spin, charge and orbital degrees of freedom and their coupling to the lattice. Topological frustration of the spinel lattice due to tetrahedral arrangement of the magnetic sublattices, i.e., geometric frustration, and bond frustration due to competing ferro- and antiferromagnetic exchange interactions yield additional complexity. ZnCr2Se4 spinel orders antiferromagnetically below TN ≈ 21 K despite the dominance of the strong ferromagnetic exchange. It reveals strong spin-lattice coupling, manifesting negative thermal expansion, colossal magnetostriction, and spin Jahn-Teller effect [1]. Here we report on the structural and magnetic correlations in ZnCr2Se4 single crystals probed by ultrasound at different temperatures and magnetic fields. The single crystals were grown by chemical transport reactions using bromine as transport agent. The measurements of the velocity and attenuation of longitudinal waves were performed with wave vector k and polarization u parallel to all three main crystallographic cubic axes.Fig.1 shows the field dependencies of the relative change of the sound velocity Δv/v for ZnCr2Se4 single crystal measured at different temperatures at frequency of 62 MHz. In the paramagnetic state, above TN, the sound velocity shows non-monotonic field dependence. At temperatures below TN, Δv/v exhibits a deep minimum at fields corresponding to an inflexion point of the magnetization curve. With increasing temperatures the minimum in Δv/v continuously shifts to lower fields. At 2 K the sound velocity manifests two plateaus above the fields of 5.5 and 10 T, which correspond to magneto-structural states with different stiffness. The first plateau in Δv/v above 5.5 T can be associated with a state following a structural transition from the tetragonal to cubic phase. The second plateau in fields above 10 T corresponds to a state in which the magnetization reaches full saturation of 6 μB/f.u. expected for Cr3+ ions in a 3d3 state. Pronounced field induces anomalies detected in the sound velocity prove remarkable spin-lattice correlations in this material with frustrated magnetic interactions. 6 [1] J. Hemberger et al., Phys. Rev. Lett. 98 (2007), 147203.