Fifty-two healthy mother--infant pairs were referred to the paediatric clinic of Malmo General Hospital because of nursing problems. Observation of nursing behaviour showed that almost all these problems were connected to incorrect sucking technique. Only three of the infants sucked correctly, with mouth wide open and tongue under the areola. In a control group of 40 mother--infant pairs without nursing problems, 36 sucked correctly. The introduction of a bottle and the use of pacifiers seemed to interfere with the course of normal nursing.