Background: There is a clear relationship between elevations in the maternal 75-g Oral Glucose Tolerance Test (OGTT) results and adverse pregnancy outcomes. Accurate and timely gestational diabetes mellitus (GDM) diagnosis and management is crucial for best practice. A one step universal screening for GDM with the OGTT is planned. Aim: To examine current practice in the ACT region to prepare for this change. Method: The essential elements of the OGTT (gestation, fasting and resting states, consuming and digesting all of the correct solution, collection and analysis of blood samples) which ensure accuracy were examined using three validated tools: all pathology facilities conducting the OGTT for GDM diagnosis completed a survey; a stratified random selection of these centres were visited to observe the OGTT; and 60 pregnant women (50 GDM, 10 non-GDM) completed a questionnaire. The three tools were based on a pathology policy and procedure for OGTT, reviewed by a reference group, trialled and accepted by a Survey Committee. Descriptive analysis was performed, with qualitative data analysed using a thematic approach. Results from the three methods were triangulated to validate the findings. Results: All 56 pathology centres in the region participated. Of these 47 (84%) are currently performing OGTT for GDM, albeit infrequently in many centres. The sixty women and forty-seven centres reported very high compliance with the relevant essential elements of the OGTT. Visits to the eight selected centres confirmed high quality testing although key areas for improvement were identified, including drinking of the correct solution and the timing of blood sample collection. Women reported issues with timeliness of testing, receiving results and the quality of information received. Conclusion: There is accurate practice of the OGTT in the ACT region providing correct procedure is consistently followed. Timeliness and quality feedback could improve what is mainly a positive experience for women. The ACT region is well placed to adopt the one step screening for GDM including absorbing the expected four fold increased number of OGTT.