While the harmful effects of alcohol during pregnancy are well-established, the consequences of alcohol intake during lactation have been far less examined. We reviewed available data on the prevalence of alcohol intake during lactation, the influence of alcohol on breastfeeding, the pharmacokinetics of alcohol in lactating women and nursing infants and the effects of alcohol intake on nursing infants. A systematic search was performed in PubMed from origin to May 2013, and 41 publications were included in the review. Approximately half of all lactating women in Western countries consume alcohol while breastfeeding. Alcohol intake inhibits the milk ejection reflex, causing a temporary decrease in milk yield. The alcohol concentrations in breast milk closely resemble those in maternal blood. The amount of alcohol presented to nursing infants through breast milk is approximately 5-6% of the weight-adjusted maternal dose, and even in a theoretical case of binge drinking, the children would not be subjected to clinically relevant amounts of alcohol. Newborns metabolize alcohol at approximately half the rate of adults. Minute behavioural changes in infants exposed to alcohol-containing milk have been reported, but the literature is contradictory. Any long-term consequences for the children of alcohol-abusing mothers are yet unknown, but occasional drinking while breastfeeding has not been convincingly shown to adversely affect nursing infants. In conclusion, special recommendations aimed at lactating women are not warranted. Instead, lactating women should simply follow standard recommendations on alcohol consumption.