Abstract: A remote slit impact air sampler for recovering viable air borne organisms from a known volume of ambient air. The remote sampler is employed with a sealed sample chamber within which a test plate upon a turntable is rotated beneath a slit type sample inlet. During operation, air passing through the sample slit is accelerated to a velocity that insures impingement of particulate matter from the sampled air volume onto the surface of a nutrient growth medium located within the test plate. Particulate matter and associated bacterial organisms within the sampled air volume are retained upon the surface of the test plate while the sampled air volume is evacuated from the sample chamber through an air outlet, and is then exhausted away from the critical environment at the controller means. Following sampling, the test plate is incubated for a predetermined period of time following which bacterial colony forming units may be quantified.