Mean and fluctuating spectral radiation intensities were measured for nonpremixed turbulent hydrogen jet flames burning in still air. Intensities of radiation fluctuations of 20–110 percent, were observed, providing direct evidence of turbulence/radiation interactions in these flames. Radiation fluctuation were analyzed using a narrow-band radiation model combined with a stochastic simulation of scalar property variations along the radiation path. There was encouraging agreement between predicted and measured mean and fluctuating values, probability density functions, and temporal power spectral densities of spectral radiation intensities, except for spikes in the spectra associated with the release of coherent structures which become more prominent as effects of buoyancy increase. Similar to the findings of others, mean radiation levels were generally underestimated by predictions based on mean scalar properties.