The interband transitions in single‐crystal GaN films grown by metalorganic chemical vapor deposition (MOCVD) have been studied as a function of temperature (15≤T≤300 K) by reflectance and photoluminescence measurements. At low temperatures, well‐resolved spectral features corresponding to the GaN band structure were observed. The energies of the excitonic interband &Ggr;V9−&Ggr;C7,&Ggr;V7(upper band)−&Ggr;C7and &Ggr;V7(lower band)−&Ggr;C7transitions are found to be 3.485, 3.493, and 3.518 eV at 15 K, respectively, for the MOCVD GaN. The spectral features are broadened and shift to lower energy as temperature increases. At room temperature (300 K), the &Ggr;V9−&Ggr;C7and &Ggr;V7(upper band) −&Ggr;C7transition energies of this wide band‐gap material are determined to be 3.420 and 3.428 eV, respectively. The temperature dependence of these two transitions have been determined using the Varshni empirical relation. Our results yieldE0(T)=3.486–8.32×10−4T2/(835.6+T) eV for the &Ggr;V9−&Ggr;C7transition andE0(T)=3.494–10.9×10−4T2/(1194.6+T) eV for the &Ggr;V7(upper band) −&Ggr;C7transition. ©1995 American Institute of Physics.