OBJECTIVE The aim of the study was to develop an instrument that can be used for accurate assessment of nurses' and midwives' attitudes toward breastfeeding in a group of midwives, maternity-nursing staff and postnatal nurses experienced in breastfeeding counselling. METHODS An instrument based on WHO standards was developed to measure breastfeeding attitudes. In all, 168 healthcare professionals filled in the instrument. A factor analysis using maximum likelihood and varimax rotation was performed. Spearman's correlation was used to correlate factorial dimensions and self-described interest in breastfeeding. RESULTS By means of factor analysis four factors were identified: the "regulating" factor focused on regulating the mothers' breastfeeding management, the "facilitating" factor focused on making it easy for mothers to manage their breastfeeding, the "disempowering" factor focused on giving advice, disregarding the needs of the mother being counselled, and the "breastfeeding antipathy" factor focused on insufficient, basic, breastfeeding knowledge and aversive reactions to breastfeeding. Midwives rated higher on the facilitating factor and breastfeeding antipathy factor and lower on the regulating factor than postnatal nurses. Breastfeeding interest was positively correlated with the facilitating factor, and negatively with the disempowering factor and the breastfeeding antipathy factor. CONCLUSIONS This instrument provides a picture of health professionals' attitudes towards breastfeeding. Four factors were identified in order of importance: regulating, facilitating, disempowering, and breastfeeding antipathy factors. Harmful attitudes were identified and suggested a need for educational programmes to help health professionals to reconcile damaging values, in order to improve breastfeeding counselling.