The compatibility of tungsten, W-0.9wt%Cb, W-10wt%Re, W-25wt%Re, TZM (Mo-0.5wt%Ti-0.08 wt%Zr), Mo-50wt%Re, and rhenium in static lithium was determined. Exposures were at 2500, 2800, and 3000°F for periods of 100 and 1000 h. Exposures were conducted in TZM containers for all alloys tested. The results obtained must be viewed in light of the dissimilar capsule employed. The tungsten-base materials were not attacked by lithium after 100- or 1000-h exposure at 2500°F. At 2800°F, all of the tungsten-base materials exhibited varying degrees of surface dissolution and grain-boundary penetration. TZM and Mo-50wt%Re alloys were resistant to attack by lithium at up to 3000°F for 100- and 1000-h exposure. Unalloyed rhenium underwent dissimilar metal interaction while immersed in lithium in TZM test capsules for 1000 h at 2500°F and 100 h at 3000°F. Molybdenum was transferred from the TZM corrosion capsule to the rhenium where alloying occurred.