To determine the critical facilitating and impeding factors underlying successful implementation of a method to detect child abuse based on parental rather than child characteristics known as the Hague Protocol. The original implementation region of the protocol (The Hague) was compared to a new implementation region (Friesland), using analysis of referrals, focus group interviews (n=6) at the Emergency departments (ED) and at the Reporting Centers for Child abuse and Neglect (RCCAN) as well as questionnaires (n=76) at the EDs. Implementation of the Hague Protocol substantially increased the number of referrals to the RCCAN in both regions. In Friesland, the new implementation region, the number of referrals increased from 2 out of 92,464 patients (three per 100,000) to 108 out of 167,037 patients (62 per 100,000). However in Friesland, child abuse was confirmed in a substantially lower percentage of cases relative to the initial implementation region (62% vs. 91%, respectively). Follow-up analyses suggest that this lower positive predictive value may be due to the lack of training for RCCAN professionals concerning the Hague Protocol. The focus group interviews and questionnaires point to time limitations as the main impediment for implementation, whereas an implementation coach has been mentioned as the most important facilitating factor for success. The Hague Protocol can be used to detect child abuse beyond the initial implementation region. However, training is essential in order to assure a consistent evaluation by the RCCAN.