We report a study of single-crystal Raman scattering, powder synchrotron X-ray and neutron diffraction as well as specific heat for the layered compound K2Na[Ag(CN)2]3 in the temperature range 2–300 K. Analysis of the Raman scattering data provides evidence for structural changes at approximately 210 K. Synchrotron X-ray and neutron powder diffraction results indicate essential, gradual changes...