Abstract: The degree of air pollution in Quetta city was determined on heavy traffic areas using roadside trees as an indicator. The leaves of Cupressus sp., Fraxinus excelsior, Pinus longifolia, Rubinea pseudoaccasia were collected and analyzed for their macro, micro elements and heavy metal concentration. These elements were detected and estimated by using atomic absorption spectrophotometer. Significantly high contents of zinc, manganese, lead and cadmium were found. These are highly toxic for all living systems. The common source of these elements on tree leaves is motor vehicles. M.A. Jinnah road was found to be most polluted.