Objectives. To describe how Finnish public health nurses identify and intervene in child maltreatment and how they implement the National Clinical Guideline in their work. Design and Sample. Cross-sectional survey of 367 public health nurses in Finland. Measures. A web-based questionnaire developed based on the content areas of the guideline: identifying, intervening, and implementing. Results. The respondents reported they identify child maltreatment moderately (mean 3.38), intervene in it better (4.15), and implement the guideline moderately (3.43, scale between 1 and 6). Those with experience of working with maltreated children reported they identify them better (P < 0.001), intervene better (P < 0.001), and implement the guideline better (P < 0.001) than those with no experience. This difference was also found for those who were aware of the guideline, had read it, and participated in training on child maltreatment, as compared to those who were not aware of the guideline, had not read it, or had not participated in such training. Conclusions. The public health nurses worked quite well with children who had experienced maltreatment and families. However, the results point out several developmental targets for increasing training on child maltreatment, for devising recommendations for child maltreatment, and for applying these recommendations systematically in practice.