Air pollution in urban areas due to automotive and industrial emissions is a global problem, including the city of Quito- Ecuador. In this context, previous studies have pointed out the effective use of bioindicators of air quality using epiphytic cryptogams (bryophytes and lichens), which are pollutant-sensitive organisms because they absorb water and nutrients from the environment. In this study, we determined for the first time the changes in the richness and composition epiphytic cryptogams in the host tree Schinus molle comparing areas of high, medium, and low vehicular traffic. For this purpose, we registered the frequency and coverage of lichens and bryophytes with a grid of 10 x 50 cm, divided into twenty squares of 5 x 5 cm on Schinus molle trees. We recorded 30 species (23 lichens and 7 bryophytes). Richness, cover and diversity did not indicate changes in relation to vehicular traffic, however, the composition of the communities indicated slight changes in relation to vehicular traffic. Species composition indicated changes in relation to vehicular traffic, where species of the genera Leptogium and Teloschistes were dominant in low traffic areas, conversely species of genera Candelaria, Physcia and Frullania was observed in areas with higher traffic that are tolerant to pollution. Schinus molle is a very important species as a refuge for diversity of epiphytic cryptogams in urban areas.