The aims were to identify what the child health nurse believed was expected of her by women who had recently become mothers, primipara and multipara, to investigate which problems the nurse found most difficult to deal with and to analyse why they were difficult. The grounded theory method was employed for conducting interviews with 15 nurses. The data analysis showed that the nurses thought mothers expected care of the infant and the family from the nurse, comprising support, advice and child health assessments. What the nurses found most difficult to deal with were obstacles to interaction with mothers such as motherhood problems, hidden, social and organisational problems. They wanted to have a positive interaction with mothers to be able to fulfil the task of supporting parents and identifying risks to the child's healthy upbringing. This task places great demands on nurses' competence and knowledge about the child and family.