A new idea of generating bacteria bioaerosols by utilizing an electrospray method was suggested and tested in this study. Liquid suspensions containing Staphylococcus epidermidis and Escherichia coli bacteria were sprayed by means of a specially designed electrospray system in a cone-jet mode, and measurements were taken of the biological viability as well as the physical properties of the electrosprayed bioaerosols. The tested bacterial suspensions had around 10(7) CFU/ml concentrations and the suspensions of electrosprayed particles sampled with a biosampler had concentrations that ranged from 10(5) to 10(6) CFU/ml. The experimental results show that the electrospray method can be used to generate viable bacteria bioaerosols with a highly electrically charged status. (C) 2007 Elsevier Ltd. All rights reserved.