The fluorescence from high-pressure argon plasmas (1-30 bar) has been excited with an intense flash X-ray device. For the first time a spectrum from 110 to 700 nm has been recorded under such conditions. The spectra obtained in the UV-VUV were very similar to those recorded with alpha -particle excitation at equivalent pressures. The dominant features were the so-called second and third continua of argon. The visible fluorescence was found to be negligible in comparison with the VUV continua.