Several limitations have been identified with case control and cohort studies assessed the relationship between maternal drinking during pregnancy and the risk of adverse effects in pregnancy, including recall/misclassification bias in studies collecting data retrospectively, and difficulties in retaining high-risk women in longitudinal studies. The aims of this study were to examine the pregnancy outcomes for mothers who have an alcohol-related diagnosis, stratified by Aboriginal status. The design of this study was population-based cohort study using linked Western Australian (WA) health data to identified women who have had a birth recorded on the Midwives Notification Systems in WA (1983-2007). Mothers with an alcohol related diagnosis (ICD, 9th/10th revisions) (n=6,897 non-Aboriginal, and n=3,314 Aboriginal mothers), a proxy for alcohol-use disorders and their offspring (n=13,933 non-Aboriginal, and n=9,947 Aboriginal infants) comprised the exposed cohort. Mothers without an alcohol-related diagnosis (n=37,947 non-Aboriginal, and n=9,741 Aboriginal mothers) and their offspring (n=40,397 non-Aboriginal, and n=20,928 Aboriginal infants) comprised the comparison cohort. The results showed that the 1.4 fold (aOR 1.42, 95% CI: 1.09-1.87) increased odds of placental abruption were observed among non-Aboriginal mothers, but not for Aboriginal mothers. The odds ratios for non-Aboriginal mothers with any alcohol use diagnosis were 1.30 (95% CI: 1.07-1.57) for threatened preterm labour, and 1.27 (95% CI: 1.15-1.41) for pre-labour rupture of the membranes, and for Aboriginal mothers 1.56 (95% CI: 1.32-1.83), and 1.34 (95% CI: 1.22-1.47), respectively. The odds ratios increased when an alcohol related diagnosis was recorded during pregnancy. It can be concluded that alcohol related diagnosis among non-Aboriginal and Aboriginal mothers is associated with the range of pregnancy complications. Keywords: alcohol, pregnancy complications, cohort study, data linkage