This study explores child health care nurses' pedagogical knowledge when supporting parents in their parenthood using various teaching practices, that is how to organise and process the content during parent education groups in primary health care. The aim is to identify teaching practices used by child health care nurses and to analyse such practices with regard to Aristotle's three forms of knowledge to comprehensively examine child health care nurses' use of knowledge in practice. A qualitative methodological design alongside the analysis of video-recordings was used. The results showed that child health care nurses used four teaching practices: lecturing, demonstration, conversation and supervision. Their use of episteme was prominent, but they also seemed to master techne in combination with episteme during the first three teaching practices. During the conversation teaching practice, the child health nurses rarely succeeded. Consequently, they missed opportunities to identify mothers' expressed concerns and to act in the best interests of both the mothers and their infants by the use of phronesis. In health care, however, theoretical episteme is superordinate to productive knowledge or phronesis, which also became evident in this study. Nevertheless, more interactive pedagogical practices are needed if more use of phronesis is to become a reality in parent education groups.