A high volume virtual impactor for sampling atmospheric aerosols has a plurality of inlet nozzles and associated receiving tubes mounted in a common frame or housing having passageways which divide the airflow through the inlet nozzles into a major flow and a minor flow. The minor flow, or the smaller volume flow, passes through the respective receiving tube into a common chamber, while the major flow is caused to turn 180.degree. between flow exit of the inlet nozzle and its associated receiving tubes and pass as through a small particle filter. The impactors are arranged in oppositely facing and aligned pairs. The exhaust ends of the receiving tubes in a part face each other, so that the flows from the receiving tubes will intermix in the center of a chamber, to prevent substantial particle impingement against the housing surfaces. The filters are located at the bottom of the housing to minimize losses. Use of several parallel vertical impactor inlet nozzles and receiving tubes permits a high total flow rate while keeping the flow rate through any individual tube at a reasonable value and thus within good operating parameters. Because the input nozzles and receiving tubes are mounted in a single frame, the mounting holes for them can be machined precisely to insure near perfect alignment and thus enhance operation.