We conducted a retrospective review of 540 women with gestational diabetes managed by our Service between 1990 and 1996. The aim was to determine the recurrence rate of gestational diabetes and the factors associated with recurrence. Of 117 women who had a subsequent pregnancy, 82 (70%) had a recurrence of gestational diabetes according to criteria where the fasting glucose value > or = 5.5 and/or 1 hour > or = 10.0 and/or 2-hour > or = 8.0 mmol/L after a 75 g oral glucose load. The recurrence rate was 62.4% (58), using the criteria of the Australian Diabetes in Pregnancy Society (ADIPS). Older age in both the index and subsequent pregnancy and insulin requirement during the index pregnancy were the strongest predictors for recurrence of gestational diabetes. Non-English speaking country of birth, higher diagnostic glucose tolerance test (GTT) levels, greater prepregnancy BMI and weight gain between pregnancies were also associated with recurrence.