It has been ten years since the subject of chemical disinfectants was last covered in the Annual Review of Microbiology. No attempt is made in this review to include all the data which have appeared since that time as the volume of work published in the last decade and the amount of space allotted for this review makes this an impossibility. Rather, this article is intended to serve more or lass as a status report on chemical disinfection as of the present moment, with passing comment on certain areas in which the greatest recent activity had taken place. As such, it represents to a large degree the bias of the authors, who arbitrarily select that material which was of most interest to them.