A study, funded by Department of Environment and Heritage's Living Cities Program, collected samples of both PM2.5 (fine particles) and PM2.5-10 (coarse particles) over a 12-month period during 2003-2004 in Melbourne, Sydney, Brisbane and Adelaide. 24-hour aerosol samples were collected in six-day cycle using dichotomous samplers at two sites from a typical urban and typical suburban monitoring site operated by the state EPA in each city. ANSTO performed gravimetric analysis and accelerator-based ion beam analysis which provided information on F, Na, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Cu, Ni, Zn, Sr, Br and Pb to determine the elemental composition of the aerosols. The overall average concentration of fine particles was 5.6 姯m3, while PM2.5-10 10 姯m3. The concentrations of fine particles did not exceed USEPA air quality standards and proposed 24-hour and annual NEPM goal. The elemental composition of PM2.5-10 particles was dominated by Si, Fe, Al, K, Ca, Na and Cl, while black carbon, S, Na and Cl dominated the fine fraction. V, Cr, Ni and Co were below the minimum detection limits in most of the samples. The concentrations of Mn, Cu, Zn and Pb were measured below 0.01 姯m3 in the coarse particles and below 0.02 姯m3 in fine aerosols. The measured concentrations of heavy metals exhibit spatial and temporal variations.