During the past several years, research related to screening for Chlamydia trachomatis has flourished, with new diagnostic tests, new methods for specimen collection, and new prevalence data in different populations. Public health endorsements for screening are now more specific than ever, yet several important clinical and laboratory questions remain, including questions concerning who to screen and how often to screen. Additional important research is addressing issues related to assay validity, efficacy of screening in different populations, and feasibility of screening on the level of the individual patient and the level of the community and health care system. This article discusses major research findings related to chlamydial screening from the past several years and suggests areas in which additional research is needed.