A method of detection of bacterial aerosols by means of membrane filtres is described. The suspension obtained by dissolving the membrane filter was afterwards cultured. The membrane filter together with the captured microorganisms, was dissolved in methyl or ethylglycol. It was found that dilute methyl or ethylglycol solutions do not significantly inhibit the majority of bacteria. The results were compared with the results of culture of microorganisms captured from the air by the impaction method (using a type S Chirana aeroscope) the conversion factor between the aeroscope and culture of the suspension after dissolving the membrane filter being about 103.