Genital chlamydial infection is the commonest curable sexually transmitted disease in England and Wales. It is a major cause of pelvic inflammatory disease, ectopic pregnancy, and infertility. For this reason, research, health promotion, and disease prevention initiatives have focused on women. Screening women for chlamydial infection is concerned mainly with identifying and reducing complications among those already infected (secondary prevention), rather than with preventing new infections (primary prevention). Screening men for genital chlamydial infection, a strategy for preventing new infections in women, has been considered problematic because of the cost, the invasiveness of sampling procedures, and the need to screen in clinical settings. The availability of nucleic acid amplification diagnostic tests challenges these limitations and offers new opportunities for actively including men in disease prevention. This article reviews the arguments for and against screening men for genital chlamydial infection and discusses possible strategies for its implementation.