An epitaxial GaN layer was doped with the radioactive isotope 191 Pt by ion implantation at the online mass separator facility ISOLDE at CERN (energy 60 keV, maximum dose of 3 Â 10 12 ions/cm 2 ). The isotope 191 Pt decays with a halflife of 2.9 d into stable 191 Ir. After annealing at 1300 K several Pt-related photoluminescence transitions in the nearinfrared region are detected. Platinum is found to produce near-infrared luminescence consisting of two single transitions ðPt 1 Þ at 1.461 and 1.446 eV followed by a set of transitions ðPt 2 Þ starting at 1.273 eV each separated by 15 meV in energy. The photoluminescence spectra recorded within 30 days after implantation will be presented. The half-lives resulting from exponential fits to the intensities of these optical transitions yield half-lives of t 1=2 ðPt 1 Þ ¼ ð2:670:6Þ d and t 1=2 ðPt 2 Þ ¼ ð3:170:3Þ d, respectively, in very good agreement with the nuclear half-life of the isotope 191 Pt. Therefore, the recombination centers responsible for this near-infrared luminescence have to involve exactly one Pt atom. We do not observe any other changes in the whole spectral region between 0.9 up to 3.5 eV, in particular no new lines turn up, so we conclude that iridium does not introduce any optically active recombination centers in GaN.