Aims: To evaluate an existing register for long-term follow-up of women who have been diagnosed with GDM. Background: Women who have had gestational diabetes mellitus (GDM) are at increased risk of developing type 2 diabetes. Early detection and management of type 2 diabetes are important for reducing associated complications and costs. Conclusions: Expansion of the GDM Recall Register is likely to result in increased opportunities for early detection of diabetes for this high-risk group in South Australia, therefore allowing earlier intervention and treatment to prevent or reduce serious, costly diabetes-related complications. Methods: Recruitment to the GDM Recall Register began at the diabetes centres of two hospitals in South Australia from July 2002, and was expanded to include a third hospital from September 2005. Women enrolled on the Register are sent an annual letter reminding them that they are at increased risk of developing type 2 diabetes and encouraging them to get their blood glucose checked. An update form is also included for women to complete and return to the Register. Results: As at 30 June 2009, 817 women were enrolled on the Register. Of women diagnosed with GDM at the participating hospital sites, recruitment to the Register was 68.4% in 2002 and 64.4% in 2007. Of the 429 women who had been sent their first reminder letter, 46.4% had returned the update form. Of these, 56.3% had undergone a glucose test for diabetes. Two women reported developing type 2 diabetes. Refereed/Peer-reviewed