AbstractThe luminosity function of planetary nebula populations in galaxies at distances within 10–15 Mpc exhibits a cut-off at bright magnitudes and a functional form that is observed to be invariant among different galactic morphological types. Therefore, it is used as a secondary distance indicator applicable to both early- and late-type galaxies. Recent deep surveys of planetary nebula populations in brightest cluster galaxies (BCGs) seem to indicate that their luminosity functions deviate from those observed in the nearby galaxies. We discuss the evidence for such deviations in the Virgo Cluster, and indicate which physical mechanisms may alter the evolution of a planetary nebula envelope and its central star in the halo of BCGs. We then discuss preliminary results for distances to the Virgo, Hydra i, and Coma Clusters based on the observed planetary nebulae luminosity functions.