In order to develop a possible strategy for chlamydia testing throughout the British Pregnancy Advisory Service (BPAS), it was decided to first find the prevalence of the infection in women attending and to examine the practicalities involved in offering tests and dealing with positive results. Urine samples at initial consultation were tested by a method based on the Ligase Chain Reaction (LCR). Five hundred and eighty seven women were tested with an overall chlamydia positivity of 8.1 per cent, but of 12.4 per cent (25/202) in women up to and including 20 years of age. Tests in women over 25 years showed a positivity of only 0.7 per cent (1/147). Urine testing proved to be a convenient, non-intrusive means of chlamydia detection with the potential to lead to prompt management of positive cases. However, in comparison with EIA testing of endocervical swabs, detection of chlamydia in the population studied was not enhanced and some limitations were demonstrated, imposed by requirements for controlled temperature for transport and storage of specimens. Alternative approaches to testing and management was discussed. The time and commitment required to offer this service effectively were observed to be important factors when staff and client were focused on the direct issues relating to the current pregnancy. Modified request forms enabled uniform data to be collated in the laboratory and compared with that from other services currently studied. Ongoing monitoring of chlamydia positivity in this nationwide termination service could provide useful sentinel data about the infection.