Homogeneous radiation damage was induced in ∼250-nm-thick In 0.18 Ga 0.82 N and Al 0.2 Ga 0.8 N films by irradiation with 8.9MeV Bi 33+ ions at room temperature. The ion fluence was in the range from 5×10 11 to 5×10 13 cm −2 . From the Rutherford backscattering/channeling (RBS/C) measurements, it is shown that Al 0.2 Ga 0.8 N had a radiation resistance at least one order of magnitude higher than In 0.18 Ga 0.82 N. When the ion fluence was increased from 1×10 13 to 5×10 13 cm −2 , enhanced surface peaks were observed in the RBS/C spectra for both the In 0.18 Ga 0.82 N and Al 0.2 Ga 0.8 N films, which may be attributed to the high charge state of the incident ions. Moreover, from the Raman spectra measurements, the evolution of the disorder-related B1 bands and TO-like peaks with the fluence was observed for the In 0.18 Ga 0.82 N and Al 0.2 Ga 0.8 N films, respectively.