OBJECTIVE We studied outcome of pregnancy among immigrant women with diabetes. The women came from regions of the world with high incidence of impaired glucose tolerance and type 2 diabetes. Prevalences, secular trends, and sociodemographic risk factors of diabetes were also explored. METHODS Data from the Medical Birth Registry of Norway on all births from 1988 to 1998 for mothers born in South Asia and North Africa (11,268) and Norway (601,785) were analyzed. RESULTS The prevalence of pregestational diabetes among the immigrants was 8.9/1,000 births, which was more than twice the rate among ethnic Norwegians (3.6/1,000). Time trends indicated increasing prevalences in both groups. Among the immigrants, diabetes was closely associated with maternal age. Maternal diabetes was associated with a significantly increased risk of pregnancy complications in both study groups. Increased risks were found for low birth weight, macrosomia, preterm birth, preeclampsia, and cesarean sections. Among ethnic Norwegians, maternal diabetes conferred a significantly increased risk of infant perinatal death (odds ratio 2.00, 95% CI 1,44-2.77). In the sample of immigrant women with predominantly type 2 diabetes, maternal diabetes was not significantly associated with perinatal death or congenital malformations in the offspring. CONCLUSIONS The high prevalence of diabetes among immigrants from South Asia and North Africa represents a challenge for health care providers. To prevent adverse pregnancy outcomes and later cardiovascular and renal morbidity among these groups, early diagnosis of diabetes, adequate metabolic control, and relevant preventive measures are warranted.