On April 19th, 2013, a workshop was held at the Helmholtz Institute Jena on the subject “Wavelength standards in the x-ray region”. The participants came from DESY – Hamburg, ILL – Grenoble, PTB – Braunschweig, Université P. et M. Curie – Paris, Institut des NanoSciences de Paris, MPI-K – Heidelberg and from GSI-Helmholtzzentrum – Darmstadt. Topics discussed included QED in the heaviest highly-charged ions, various methods of accurate wavelength determination and referencing in the spectral range spanning from soft x rays to gamma rays as well as present and future high-precision metrology.