Lichens diversities are informative indicators for assessing impacts of air pollution, climate change, environmental health, volcanic activities, habitat heterogeneity and continuity. Lacking roots, vascular tissues, stomata and waxy cuticle, they absorb and accumulate airborne nutrients/pollutants from the atmosphere over their entire surface. Halogens, especially fluorides are released into the atmosphere in large amounts by volcanic eruptions and their pollutants levels in lichens can be determined quantitatively by chemical analysis of species. The objective of this study was to examine the lichens potentials on Mount Cameroon (MC) as bio-monitors and bio-accumulators for some halogens (F, Cl, Br) levels. To achieve this objective, 34 lichen species were analysed using selective ion electrode. The species were collected from eight sampling sites on two flanks of MC at elevations ranging from 3-2178 m above sea level.