The purpose of this retrospective study was to find out if more effort should be applied to the diagnosis of extremely large infants, with a birth weight of 5,000 grams or more, and if elective caesarean section can be recommended. In the Department of Obstetrics, Herning Central Hospital, Denmark, 67 mothers delivered an infant with a birth weight of 5000 g or more over a ten year period. This index group was compared with a matched group with infants of normal weight. The result showed significantly more caesarean sections in the index group (24% versus 5%, p = 0.002). Shoulder dystocia and Duchenne-Erb's palsy were more frequent as well. Sixteen percent in the index group were admitted to the paediatric department, but the Apgar scores were not significantly lower. Except for one, all the infants showed complete recovery. In conclusion, elective caesarean section can not be generally recommended for an estimated birthweight exceeding 5,000 g, if a trained obstetrician is present at delivery.