The transverse momentum () spectrum of prompt mesons and their antiparticles has been measured via the hadronic decay channels and in and PbPb collisions at a centre-of-mass energy of 5.02 TeV per nucleon pair with the CMS detector at the LHC. The measurement is performed in the meson range of 2–100 and in the rapidity range of . The (PbPb) dataset used for this analysis corresponds to an integrated luminosity of 27.4 pb−1 (530 μb−1 ). The measured meson spectrum in pp collisions is well described by perturbative QCD calculations. The nuclear modification factor, comparing meson yields in PbPb and collisions, was extracted for both minimum-bias and the 10% most central PbPb interactions. For central events, the meson yield in the PbPb collisions is suppressed by a factor of 5–6 compared to the reference in the range of 6–10. For mesons in the high- range of 60–100, a significantly smaller suppression is observed. The results are also compared to theoretical calculations.