Particulate Matter (PM) is a significant source of air pollution component that has been associated to a number of adverse health and environmental effects resulting from factors which influence its characteristics, composition and distribution in ambient atmosphere. High concentrations of PM can also result in secondary effects that include heart failure, aggravation of diabetes, neuro-degenerative diseases, skin problems, and can also cause lung diseases. Metals present in suspended particulate matter are also considered to be a health hazard since they can be absorbed into human lung tissue during breathing.The focus of the present work was to describe urban ambient particulate matter in terms of its metal content and then to evaluate its distribution in the atmosphere of metropolitan Karachi, Pakistan.