Purpose This study evaluated the extent to which migrant women participate in the mandatory oral glucose tolerance test (OGTT) for gestational diabetes mellitus (GDM) screening in Austria. Methods A retrospective data analysis was carried out of births at an obstetrics unit in a university hospital between January 2013 and December 2015. The inclusion criteria were singleton pregnancies, live births, birth weight 3500, and no preexisting diabetes mellitus. The patients extramurally obtained OGTT values and history of GDM were checked. If the mothers country of birth was not Austria, the woman was classified as a migrant. Three groups were defined: group 1women with normal OGTT; group 2women with pathological OGTT; and group 3women without OGTT or with an incomplete OGTT. Main outcome measures: Numbers of complete and incomplete OGTTs and rate of women with pathological OGTTs not treated in accordance with the guidelines among mothers born in Austria or migrants. The groups were compared using the t-test, chi-squared test, or Fishers exact test Results A total of 3293 births met the inclusion criteria, and 43.52% of all mothers were migrants; 16.8% of all women had pathological OGTT findings. Only 60.1% of the latter received treatment in accordance with the guidelines. The proportion of mothers born in Austria who did not have OGTTs, or only incomplete ones, was 5.4%. In the group of migrant women, the corresponding figure was 10.5% (P<0.01). Conclusions Migrant women have significantly lower rates of participation in GDM screening.