Background and Objectives: Previous epidemiological studies show that high maternal alcohol intake during pregnancy is related to offspring mortality, however, the association of high maternal alcohol intake before conception with stillbirth and infant mortality is less clear. This study investigated the association of maternal alcohol use disorder (AUD) before and during pregnancy with the risk of stillbirth and infant mortality. Methods: We conducted a nationwide cohort study of 1,995364 births in Denmark during 1980-2012. AUD diagnoses and alcoholism-related medication were retrieved from the Danish National Patient Registry and the Danish National Prescription Registry, respectively. We categorized women as having either “AUD BEFORE pregnancy only” or “any AUD DURING pregnancy”. For women with AUD diagnosed only before conception, we further categorized the recency of diagnosis into 8 years. Stillbirth and infant mortality were identified from The Danish Medical Birth Register and Danish Register of Causes of Death, respectively. We used logistic regression models to analyze the association of maternal AUD with stillbirth and infant mortality.  Results: Of 1,995364 births during 1980-2012, 8663 stillbirths and 9960 infant deaths occurred. Compared with no maternal AUD diagnosis, maternal AUD before conception was associated with 24% [95% confidence interval (CI)=1.00-1.53] and 31% (95%CI=1.10-1.57) higher odds for stillbirth and infant mortality, respectively. Recency of diagnosis before conception presented a monotonic relationship with of stillbirth and infant mortality risk. Compared with women who never had the disorder, women with AUD during pregnancy had an increased risk of having a stillbirth (OR=1.86, 95%CI=0.99-3.47) and experiencing infant mortality (OR=3.17, 95%CI=2.11-4.76). Conclusions: Maternal AUD before and during pregnancy were associated with an increased risk of stillbirth and infant mortality. This study supported that early attention to maternal AUD is a potential way to decrease risk of stillbirth and infant mortality.