Deuterium retention in two reduced-activation ferritic/martensitic (RAFM) steels, F82H (8Cr-2W) and EUROFER (9Cr-1W), was measured by nuclear reaction analysis and thermal desorption spectrometry after exposure to low-energy deuterium plasmas. In the RAFM steels, the deuterium retention was 1017–1019D/m2 and the major fraction of deuterium was retained in the near-surface layer.The surface concentrations of tungsten increased with the D ion fluence and energy due to the selective sputtering of iron and chromium. Scanning electron microscopy images clearly indicated that the surface morphology changed with increasing D fluence (i.e. the grain boundaries became more visible because of erosion by ion bombardment). At a low fluence of about 1023D/m2, deuterium retention was affected by surface modification in RAFMs.