A high‐power noble gas cw ion laser has been constructed using a tungsten disk structure capable of dissipating over 70 kW of input power. Quasi‐continuous laser outputs in the near ultraviolet have been observed at 3638 and 3511 Å of ArIII and true cw output was obtained at 3507, 4067, and 4131 Å of KrIII. The latter has been identified as a new cw laser line. Over one watt of quasi‐continuous output was demonstrated with the 3638‐Å line. However, high‐power continuous output in the uv is limited by serious optical degradation effects.