A 3600Child-proﬁle, with theoretically ordered, integral child-information visualized in one image, is designed by the Dutch preventive Child and Youth Health Care (CYHC). The introduction of this new data/information carrier gives an important incentive to enhance a transformation towards personalized health care for children and adolescents by supporting the complex medical thought process of CYHCmedical doctors (MD's). This information tool aims to eﬀectively estimate child's functioning, detect emerging health problems and inform parents and caregivers. This pilotstudy evaluatedaspects ofinter- andintra-rater reliabilityand concurrent validity ofthe 3600Childproﬁle when used by MD's to estimate functioning and needed intervention of 4-year-old children. After the development process, in January 2015, 3600Child-proﬁles (n= 26) were assessed by MD's, in the Netherlands. Each MD assessed two Childproﬁles twice and was matched to another MD receiving exactly the same two proﬁles. The paired scores and rater's scores of both time-points were compared. Rater's scores also were compared with the 26 reference tests scores. Reliability results showed Intraclass correlation coeﬃcients between 0.71 and 0.82 (overall functioning), Cohen'skappa's between0.61and0.80(psychosocial functioning)and0.46–0.47(needed intervention).Validity results showed a Spearman's correlation coeﬃcient of 0.78 (overall functioning), Cohen's kappa's of 0.43 and 0.77 (psychosocial functioning) and 0.52 (needed intervention). In conclusion, in some domains, acceptable results regarding reliability and validity are found for the visualization of integral childinformation used by CYHC-MD's to assess child-functioning after only a short training. The 3600Child-proﬁle's value on tracking change in functioning and decision-making on intervention needs further exploration.