This work presents an optimized sample digestion procedure for determining Cr in airborne particulate matter by inductively coupled plasma mass spectrometry (ICP-MS). High resolution (HR) ICP-MS is utilized to examine how the added acid mixture and subsequent evaporation process influence spectroscopic interference. Experimental results indicate that a two-step high pressure bomb acid digestion (1st step with HNO3+HClO4, and 2nd step with HF) procedure without evaporation is the optimum pre-treatment procedure for determining Cr by ICP-MS. In addition, laser ablation (LA) ICP-MS is used directly to analyze for Cr in airborne particulate matter. Results obtained by LA-ICP-MS correlate well with certified values and values obtained from the conventional acid digestion/HR-ICP-MS method. The detection limit for Cr in air particles by HR-ICP-MS with the proposed digestion method is<10 ng g(-1). Furthermore, LA-ICP-MS provides a rapid direct analytical technique with a detection limit of 0.05 mu g/filter.